diff --git a/src/Assets/AssetContainer.php b/src/Assets/AssetContainer.php
index 29765fce49..ca3e9cd3be 100644
--- a/src/Assets/AssetContainer.php
+++ b/src/Assets/AssetContainer.php
@@ -140,7 +140,7 @@ public function url()
 
         $url = rtrim($this->disk()->url('/'), '/');
 
-        return ($url === '') ? '/' : $url;
+        return URL::tidy($url);
     }
 
     /**
diff --git a/src/Facades/Endpoint/URL.php b/src/Facades/Endpoint/URL.php
index 037a1bc7cf..4ab45d9cbd 100644
--- a/src/Facades/Endpoint/URL.php
+++ b/src/Facades/Endpoint/URL.php
@@ -2,10 +2,9 @@
 
 namespace Statamic\Facades\Endpoint;
 
-use Statamic\Data\Services\ContentService;
+use Illuminate\Support\Collection;
 use Statamic\Facades\Config;
 use Statamic\Facades\Path;
-use Statamic\Facades\Pattern;
 use Statamic\Facades\Site;
 use Statamic\Support\Str;
 
@@ -14,122 +13,129 @@
  */
 class URL
 {
-    private static $externalUriCache = [];
+    private static $enforceTrailingSlashes = false;
+    private static $absoluteSiteUrlsCache;
+    private static $externalSiteUrlsCache;
+    private static $externalAppUrlsCache;
 
     /**
-     * Removes occurrences of "//" in a $path (except when part of a protocol)
-     * Alias of Path::tidy().
-     *
-     * @param  string  $url  URL to remove "//" from
-     * @return string
+     * Configure whether or not to enforce trailing slashes when normalizing URL output throughout this class.
      */
-    public function tidy($url)
+    public function enforceTrailingSlashes(bool $bool = true): void
     {
-        return Path::tidy($url);
+        self::$enforceTrailingSlashes = $bool;
     }
 
     /**
-     * Assembles a URL from an ordered list of segments.
-     *
-     * @param mixed string  Open ended number of arguments
-     * @return string
+     * Tidy a URL (normalize slashes).
      */
-    public function assemble($args)
+    public function tidy(?string $url, bool $force = false): string
     {
-        $args = func_get_args();
+        // Remove occurrences of '//', except when part of protocol.
+        $url = Path::tidy($url);
 
-        return Path::assemble($args);
+        // If URL is external to this Statamic application, we'll leave leading/trailing slashes by default.
+        if (! $force && self::isAbsolute($url) && self::isExternalToApplication($url)) {
+            return $url;
+        }
+
+        // If not an absolute URL, enforce leading slash.
+        if (! self::isAbsolute($url)) {
+            $url = Str::ensureLeft($url, '/');
+        }
+
+        // Trim trailing slash, unless enforced with `enforceTrailingSlashes()`.
+        $url = self::normalizeTrailingSlash($url);
+
+        return $url;
     }
 
     /**
-     * Get the slug of a URL.
-     *
-     * @param  string  $url  URL to parse
-     * @return string
+     * Assemble a URL from an ordered list of segments.
      */
-    public function slug($url)
+    public function assemble(?string ...$segments): string
     {
-        return basename($url);
+        return self::tidy(Path::assemble($segments));
     }
 
     /**
-     * Swaps the slug of a $url with the $slug provided.
-     *
-     * @param  string  $url  URL to modify
-     * @param  string  $slug  New slug to use
-     * @return string
+     * Get the slug at the end of a URL.
      */
-    public function replaceSlug($url, $slug)
+    public function slug(?string $url): ?string
     {
-        return Path::replaceSlug($url, $slug);
+        $url = Str::ensureRight(self::removeQueryAndFragment($url), '/');
+
+        if (parse_url($url)['path'] === '/') {
+            return null;
+        }
+
+        return basename(self::removeQueryAndFragment($url));
     }
 
     /**
-     * Get the parent URL.
-     *
-     * @param  string  $url
-     * @return string
+     * Replace the slug at the end of a URL with the provided slug.
      */
-    public function parent($url)
+    public function replaceSlug(?string $url, string $slug): string
     {
-        $url_array = explode('/', $url);
-        array_pop($url_array);
+        if (parse_url(Str::ensureRight($url, '/'))['path'] === '/') {
+            return self::tidy($url);
+        }
+
+        $parts = str($url)
+            ->split(pattern: '/([?#])/', flags: PREG_SPLIT_DELIM_CAPTURE)
+            ->all();
+
+        $url = Str::removeRight(array_shift($parts), '/');
+        $queryAndFragments = implode($parts);
 
-        $url = implode('/', $url_array);
+        $url = self::tidy(Path::replaceSlug($url, $slug));
 
-        return ($url == '') ? '/' : $url;
+        return $url.$queryAndFragments;
     }
 
     /**
-     * Checks if one URL is an ancestor of another.
+     * Get the parent URL.
      */
-    public function isAncestorOf($child, $ancestor)
+    public function parent(?string $url): string
     {
-        $child = Str::before($child, '?');
-        $child = Str::ensureRight($child, '/');
-        $ancestor = Str::ensureRight($ancestor, '/');
+        $trailingSlash = self::isAbsolute($url) && self::isExternalToApplication($url)
+            ? self::hasTrailingSlash($url)
+            : self::$enforceTrailingSlashes;
 
-        if ($child === $ancestor) {
-            return false;
+        $strMethod = $trailingSlash
+            ? 'ensureRight'
+            : 'removeRight';
+
+        $url = Str::ensureRight(self::removeQueryAndFragment($url), '/');
+
+        if (parse_url($url)['path'] !== '/') {
+            $url = preg_replace('/[^\/]*\/$/', '', $url);
         }
 
-        return Str::startsWith($child, $ancestor);
+        return Str::$strMethod(self::tidy($url), '/') ?: '/';
     }
 
     /**
-     * Make sure the site root is prepended to a URL.
-     *
-     * @param  string  $url
-     * @param  string|null  $locale
-     * @param  bool  $controller
-     * @return string
+     * Check if one URL is an ancestor of another.
      */
-    public function prependSiteRoot($url, $locale = null, $controller = true)
+    public function isAncestorOf(?string $child, ?string $ancestor): bool
     {
-        // Backwards compatibility fix:
-        // 2.1 added the $locale argument in the second position to match prependSiteurl.
-        // Before 2.1, the second argument was controller. We'll handle that here.
-        if ($locale === true || $locale === false) {
-            $controller = $locale;
-            $locale = null;
+        $child = Str::ensureRight(self::removeQueryAndFragment($child), '/');
+        $ancestor = Str::ensureRight(self::removeQueryAndFragment($ancestor), '/');
+
+        if ($child === $ancestor) {
+            return false;
         }
 
-        return self::makeRelative(
-            self::prependSiteUrl($url, $locale, $controller)
-        );
+        return Str::startsWith($child, $ancestor);
     }
 
     /**
-     * Make sure the site root url is prepended to a URL.
-     *
-     * @param  string  $url
-     * @param  string|null  $locale
-     * @param  bool  $controller
-     * @return string
+     * Prepend site URL to a URL.
      */
-    public function prependSiteUrl($url, $locale = null, $controller = true)
+    public function prependSiteUrl(?string $url, ?string $locale = null, bool $controller = true): string
     {
-        $prepend = rtrim(Config::getSiteUrl($locale), '/');
+        $prepend = Str::removeRight(Config::getSiteUrl($locale), '/');
 
         // If we don't want the front controller, we'll have to strip
         // it out since it should be in the site URL already.
@@ -139,29 +145,21 @@ public function prependSiteUrl($url, $locale = null, $controller = true)
             $prepend = Str::removeRight($prepend, $file);
         }
 
-        $prepend = Str::ensureRight($prepend, '/');
-
-        return Str::ensureLeft(ltrim($url, '/'), $prepend);
+        return self::tidy($prepend.'/'.$url);
     }
 
     /**
-     * Removes the site root url from the beginning of a URL.
-     *
-     * @param  string  $url
-     * @return string
+     * Remove current site URL from the beginning of a URL.
      */
-    public function removeSiteUrl($url)
+    public function removeSiteUrl(?string $url): string
     {
-        return preg_replace('#^'.Config::getSiteUrl().'#', '/', $url);
+        return self::tidy(preg_replace('#^'.Config::getSiteUrl().'#', '/', $url));
     }
 
     /**
-     * Make an absolute URL relative.
-     *
-     * @param  string  $url
-     * @return string
+     * Make an absolute URL relative (with leading slash).
      */
-    public function makeRelative($url)
+    public function makeRelative(?string $url): string
     {
         $parsed = parse_url($url);
 
@@ -175,102 +173,103 @@ public function makeRelative($url)
             $url .= '#'.$parsed['fragment'];
         }
 
-        return $url;
+        return self::tidy($url);
     }
 
     /**
-     * Make a relative URL absolute.
-     *
-     * @param  string  $url
-     * @return string
+     * Make a relative URL absolute (prepends domain if not already absolute).
      */
-    public function makeAbsolute($url)
+    public function makeAbsolute(?string $url): string
     {
-        // If it doesn't start with a slash, we'll just leave it as-is.
-        if (! Str::startsWith($url, '/')) {
+        // If URL is external to this Statamic application, we'll just leave it as-is.
+        if (self::isAbsolute($url) && self::isExternalToApplication($url)) {
             return $url;
         }
 
-        return self::tidy(Str::ensureLeft($url, self::getSiteUrl()));
+        if (self::isAbsolute($url)) {
+            return self::tidy($url);
+        }
+
+        $url = Str::ensureLeft($url, '/');
+        $url = Str::ensureLeft($url, self::getRequestRootUrl());
+
+        return self::tidy($url);
     }
 
     /**
      * Get the current URL.
-     *
-     * @return string
      */
-    public function getCurrent()
+    public function getCurrent(): string
     {
-        return self::format(app('request')->path());
+        return self::tidy(request()->path());
     }
 
     /**
-     * Formats a URL properly.
-     *
-     * @param  string  $url
-     * @return string
+     * Check whether a URL is absolute.
      */
-    public function format($url)
+    public function isAbsolute(?string $url): bool
     {
-        return self::tidy('/'.trim($url, '/'));
+        return Str::startsWith($url, ['http:', 'https:']);
     }
 
     /**
-     * Checks whether a URL is external or not.
-     *
-     * @param  string  $url
-     * @return bool
+     * Check whether a URL is external to current site.
      */
-    public function isExternal($url)
+    public function isExternal(?string $url): bool
     {
-        if (isset(self::$externalUriCache[$url])) {
-            return self::$externalUriCache[$url];
+        if (isset(self::$externalSiteUrlsCache[$url])) {
+            return self::$externalSiteUrlsCache[$url];
         }
 
         if (! $url) {
             return false;
         }
 
-        if (Str::startsWith($url, ['/', '#'])) {
-            return self::$externalUriCache[$url] = false;
-        }
-
-        $isExternal = ! Pattern::startsWith(
-            Str::ensureRight($url, '/'),
-            Site::current()->absoluteUrl()
-        );
+        $url = Str::ensureRight($url, '/');
 
-        self::$externalUriCache[$url] = $isExternal;
+        if (Str::startsWith($url, ['/', '?', '#'])) {
+            return self::$externalSiteUrlsCache[$url] = false;
+        }
 
-        return $isExternal;
-    }
+        $isExternal = ! Str::startsWith($url, Str::ensureRight(Site::current()->absoluteUrl(), '/'));
 
-    public function clearExternalUrlCache()
-    {
-        self::$externalUriCache = [];
+        return self::$externalSiteUrlsCache[$url] = $isExternal;
     }
 
     /**
-     * Get the current site url from Apache headers.
-     *
-     * @return string
+     * Check whether a URL is external to whole Statamic application.
      */
-    public function getSiteUrl()
+    public function isExternalToApplication(?string $url): bool
     {
-        $rootUrl = url()->to('/');
+        if (isset(self::$externalAppUrlsCache[$url])) {
+            return self::$externalAppUrlsCache[$url];
+        }
+
+        if (! $url) {
+            return false;
+        }
+
+        $url = Str::ensureRight($url, '/');
+
+        if (Str::startsWith($url, ['/', '?', '#'])) {
+            return self::$externalAppUrlsCache[$url] = false;
+        }
+
+        $isExternalToSites = self::getAbsoluteSiteUrls()
+            ->filter(fn ($siteUrl) => Str::startsWith($url, $siteUrl))
+            ->isEmpty();
 
-        return Str::ensureRight($rootUrl, '/');
+        $isExternalToCurrentRequestDomain = ! Str::startsWith($url, self::getDomainFromAbsolute(url()->to('/')));
+
+        return self::$externalAppUrlsCache[$url] = $isExternalToSites && $isExternalToCurrentRequestDomain;
     }
 
     /**
      * Encode a URL.
-     *
-     * @param  string  $url
-     * @return string
      */
-    public function encode($url)
+    public function encode(?string $url): string
     {
-        $dont_encode = [
+        $dontEncode = [
             '%2F' => '/',
             '%40' => '@',
             '%3A' => ':',
@@ -287,30 +286,13 @@ public function encode($url)
             '%25' => '%',
         ];
 
-        return strtr(rawurlencode($url), $dont_encode);
+        return self::tidy(strtr(rawurlencode($url), $dontEncode));
     }
 
     /**
-     * Given a localized URI, get the default URI.
-     *
-     * @param  string  $locale  The locale of the provided URI
-     * @param  string  $uri  The URI from which to find the default
+     * Return a gravatar image URL for an email address.
      */
-    public function getDefaultUri($locale, $uri)
-    {
-        return $uri; // TODO
-
-        return app(ContentService::class)->defaultUri($locale, $uri);
-    }
-
-    /**
-     * Return a gravatar image.
-     *
-     * @param  string  $email
-     * @param  int  $size
-     * @return string
-     */
-    public function gravatar($email, $size = null)
+    public function gravatar(string $email, ?int $size = null): string
     {
         $url = 'https://www.gravatar.com/avatar/'.e(md5(strtolower($email)));
 
@@ -323,15 +305,86 @@ public function gravatar($email, $size = null)
 
     /**
      * Remove query and fragment from end of URL.
-     *
-     * @param  string  $url
-     * @return string
      */
-    public function removeQueryAndFragment($url)
+    public function removeQueryAndFragment(?string $url): ?string
     {
         $url = Str::before($url, '?'); // Remove query params
         $url = Str::before($url, '#'); // Remove anchor fragment
 
-        return $url;
+        return self::tidy($url);
+    }
+
+    /**
+     * Clear URL property caches.
+     */
+    public function clearUrlCache(): void
+    {
+        self::$absoluteSiteUrlsCache = null;
+        self::$externalSiteUrlsCache = null;
+        self::$externalAppUrlsCache = null;
+    }
+
+    /**
+     * Normalize trailing slash before query and fragment (trims by default, but can be enforced).
+     */
+    private function normalizeTrailingSlash(?string $url): string
+    {
+        $parts = str($url)
+            ->split(pattern: '/([?#])/', flags: PREG_SPLIT_DELIM_CAPTURE)
+            ->all();
+
+        $url = array_shift($parts);
+        $queryAndFragments = implode($parts);
+
+        if (in_array($url, ['', '/'])) {
+            $url = '/';
+        } elseif (self::$enforceTrailingSlashes) {
+            $url = Str::ensureRight($url, '/');
+        } else {
+            $url = Str::removeRight($url, '/');
+        }
+
+        return $url.$queryAndFragments;
+    }
+
+    /**
+     * Get and cache absolute site URLs for external checks.
+     */
+    private function getAbsoluteSiteUrls(): Collection
+    {
+        if (self::$absoluteSiteUrlsCache) {
+            return self::$absoluteSiteUrlsCache;
+        }
+
+        return self::$absoluteSiteUrlsCache = Site::all()
+            ->map(fn ($site) => $site->rawConfig()['url'] ?? null)
+            ->filter(fn ($siteUrl) => self::isAbsolute($siteUrl))
+            ->map(fn ($siteUrl) => self::getDomainFromAbsolute($siteUrl));
+    }
+
+    /**
+     * Get the domain of an absolute URL for external checks.
+     */
+    private function getDomainFromAbsolute(string $url): string
+    {
+        return preg_replace('/(https*:\/\/[^\/]+)(.*)/', '$1', $url);
+    }
+
+    /**
+     * Get the current root URL from request headers.
+     */
+    private function hasTrailingSlash(string $url): string
+    {
+        return substr(preg_replace('/([^?#]*)(.*)/', '$1', $url), -1) === '/';
+    }
+
+    /**
+     * Get the current root URL from request headers.
+     */
+    private function getRequestRootUrl(): string
+    {
+        $rootUrl = url()->to('/');
+
+        return self::tidy($rootUrl);
     }
 }
diff --git a/src/Facades/URL.php b/src/Facades/URL.php
index a32c15e446..b970fdee5e 100644
--- a/src/Facades/URL.php
+++ b/src/Facades/URL.php
@@ -5,6 +5,8 @@
 use Illuminate\Support\Facades\Facade;
 
 /**
+ * TODO: Update these...
+ *
  * @method static string tidy($url)
  * @method static string assemble($args)
  * @method static string slug($url)
@@ -19,6 +21,7 @@
  * @method static string getCurrent()
  * @method static string format($url)
  * @method static bool isExternal($url)
+ * @method static bool isExternalToApplication($url)
  * @method static string getSiteUrl()
  * @method static string encode($url)
  * @method static mixed getDefaultUri($locale, $uri)
diff --git a/src/Imaging/GlideUrlBuilder.php b/src/Imaging/GlideUrlBuilder.php
index 5b34bf9e1d..0db9d402db 100644
--- a/src/Imaging/GlideUrlBuilder.php
+++ b/src/Imaging/GlideUrlBuilder.php
@@ -64,6 +64,8 @@ public function build($item, $params)
             $params['mark'] = 'asset::'.Str::toBase64Url($asset->containerId().'/'.$asset->path());
         }
 
-        return URL::prependSiteRoot($builder->getUrl($path, $params));
+        return URL::makeRelative(
+            URL::prependSiteUrl($builder->getUrl($path, $params))
+        );
     }
 }
diff --git a/src/Listeners/ClearState.php b/src/Listeners/ClearState.php
index 2b0fbf7148..5832245d67 100644
--- a/src/Listeners/ClearState.php
+++ b/src/Listeners/ClearState.php
@@ -10,6 +10,6 @@ class ClearState
     public function handle()
     {
         StateManager::resetState();
-        URL::clearExternalUrlCache();
+        URL::clearUrlCache();
     }
 }
diff --git a/src/Routing/Routable.php b/src/Routing/Routable.php
index b5f09c6f3b..31b9a7472a 100644
--- a/src/Routing/Routable.php
+++ b/src/Routing/Routable.php
@@ -103,11 +103,6 @@ private function makeAbsolute($url)
             return $url;
         }
 
-        $url = vsprintf('%s/%s', [
-            rtrim($this->site()->absoluteUrl(), '/'),
-            ltrim($url, '/'),
-        ]);
-
-        return $url === '/' ? $url : rtrim($url, '/');
+        return URL::tidy($this->site()->absoluteUrl().'/'.$url);
     }
 }
diff --git a/src/Sites/Site.php b/src/Sites/Site.php
index cc1f6f365a..75597284fe 100644
--- a/src/Sites/Site.php
+++ b/src/Sites/Site.php
@@ -4,6 +4,7 @@
 
 use Statamic\Contracts\Data\Augmentable;
 use Statamic\Data\HasAugmentedData;
+use Statamic\Facades\URL;
 use Statamic\Support\Arr;
 use Statamic\Support\Str;
 use Statamic\Support\TextDirection;
@@ -51,13 +52,7 @@ public function lang()
 
     public function url()
     {
-        $url = $this->config['url'];
-
-        if ($url === '/') {
-            return '/';
-        }
-
-        return Str::removeRight($url, '/');
+        return URL::tidy($this->config['url'], true);
     }
 
     public function direction()
@@ -77,22 +72,12 @@ public function attribute($key, $default = null)
 
     public function absoluteUrl()
     {
-        if (Str::startsWith($url = $this->url(), '/')) {
-            $url = Str::ensureLeft($url, request()->getSchemeAndHttpHost());
-        }
-
-        return Str::removeRight($url, '/');
+        return URL::makeAbsolute($this->url());
     }
 
     public function relativePath($url)
     {
-        $url = Str::ensureRight($url, '/');
-
-        $path = Str::removeLeft($url, $this->absoluteUrl());
-
-        $path = Str::removeRight(Str::ensureLeft($path, '/'), '/');
-
-        return $path === '' ? '/' : $path;
+        return URL::makeRelative(Str::removeLeft($url, $this->absoluteUrl()));
     }
 
     public function set($key, $value)
diff --git a/src/Stache/Repositories/TermRepository.php b/src/Stache/Repositories/TermRepository.php
index 2e4fb08ed3..a79f79b9ad 100644
--- a/src/Stache/Repositories/TermRepository.php
+++ b/src/Stache/Repositories/TermRepository.php
@@ -9,6 +9,7 @@
 use Statamic\Facades\Collection;
 use Statamic\Facades\Entry;
 use Statamic\Facades\Taxonomy;
+use Statamic\Facades\URL;
 use Statamic\Query\Scopes\AllowsScopes;
 use Statamic\Stache\Query\TermQueryBuilder;
 use Statamic\Stache\Stache;
@@ -188,7 +189,7 @@ public static function bindings(): array
 
     private function findTaxonomyHandleByUri($uri)
     {
-        return $this->stache->store('taxonomies')->index('uri')->items()->flip()->get(Str::ensureLeft($uri, '/'));
+        return $this->stache->store('taxonomies')->index('uri')->items()->flip()->get(URL::tidy($uri));
     }
 
     public function substitute($item)
diff --git a/src/Support/FileCollection.php b/src/Support/FileCollection.php
index 4aebd51509..5c6378b403 100644
--- a/src/Support/FileCollection.php
+++ b/src/Support/FileCollection.php
@@ -198,7 +198,7 @@ public function toArray()
             $gb = number_format($size / 1073741824, 2);
 
             $data[] = [
-                'file' => URL::format($path), // Todo: This will only work when using the local file adapter
+                'file' => URL::tidy($path), // Todo: This will only work when using the local file adapter
                 'filename' => $pathinfo['filename'],
                 'extension' => Arr::get($pathinfo, 'extension'),
                 'basename' => Arr::get($pathinfo, 'basename'),
diff --git a/src/Tags/Structure.php b/src/Tags/Structure.php
index 9ce1809039..727e4dec3f 100644
--- a/src/Tags/Structure.php
+++ b/src/Tags/Structure.php
@@ -137,8 +137,8 @@ public function toArray($tree, $parent = null, $depth = 1)
                 'count' => $index + 1,
                 'first' => $index === 0,
                 'last' => $index === count($tree) - 1,
-                'is_current' => ! is_null($url) && rtrim($url, '/') === rtrim($this->currentUrl, '/'),
-                'is_parent' => ! is_null($url) && $this->siteAbsoluteUrl !== $absoluteUrl && URL::isAncestorOf($this->currentUrl, $url),
+                'is_current' => ! is_null($url) && $url === $this->currentUrl,
+                'is_parent' => ! is_null($url) && $this->siteAbsoluteUrl !== $url && URL::isAncestorOf($this->currentUrl, $url),
                 'is_external' => URL::isExternal((string) $absoluteUrl),
             ], $this->params->bool('include_parents', true) ? ['parent' => $parent] : []);
         })->filter()->values();
diff --git a/src/View/Cascade.php b/src/View/Cascade.php
index e0d2d094ed..aa0f57bd14 100644
--- a/src/View/Cascade.php
+++ b/src/View/Cascade.php
@@ -195,7 +195,7 @@ private function contextualVariables()
             // Request
             'current_url' => $this->request->url(),
             'current_full_url' => $this->request->fullUrl(),
-            'current_uri' => URL::format($this->request->path()),
+            'current_uri' => URL::tidy($this->request->path()),
             'get_post' => Arr::sanitize($this->request->all()),
             'get' => Arr::sanitize($this->request->query->all()),
             'post' => $this->request->isMethod('post') ? Arr::sanitize($this->request->request->all()) : [],
diff --git a/tests/Assets/AssetRepositoryTest.php b/tests/Assets/AssetRepositoryTest.php
index b1b1635ec8..37e89e4235 100644
--- a/tests/Assets/AssetRepositoryTest.php
+++ b/tests/Assets/AssetRepositoryTest.php
@@ -76,11 +76,11 @@ public function it_resolves_the_correct_disk_from_similar_names()
 
         $foundAssetShortUrl = Asset::findByUrl($assetShortUrl->url());
         $this->assertInstanceOf(\Statamic\Contracts\Assets\Asset::class, $foundAssetShortUrl);
-        $this->assertEquals('test/foo/image_in_short.jpg', $foundAssetShortUrl->url());
+        $this->assertEquals('/test/foo/image_in_short.jpg', $foundAssetShortUrl->url());
 
         $foundAssetLongUrl = Asset::findByUrl($assetLongUrl->url());
         $this->assertInstanceOf(\Statamic\Contracts\Assets\Asset::class, $foundAssetLongUrl);
-        $this->assertEquals('test_long_url_same_beginning/foo/image_in_long.jpg', $foundAssetLongUrl->url());
+        $this->assertEquals('/test_long_url_same_beginning/foo/image_in_long.jpg', $foundAssetLongUrl->url());
     }
 
     #[Test]
diff --git a/tests/Facades/UrlTest.php b/tests/Facades/UrlTest.php
index fbfb07328c..45cbbd2591 100644
--- a/tests/Facades/UrlTest.php
+++ b/tests/Facades/UrlTest.php
@@ -5,10 +5,19 @@
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Test;
 use Statamic\Facades\URL;
+use Statamic\Support\Str;
 use Tests\TestCase;
 
 class UrlTest extends TestCase
 {
+    public function tearDown(): void
+    {
+        URL::enforceTrailingSlashes(false);
+        URL::clearUrlCache();
+
+        parent::tearDown();
+    }
+
     protected function resolveApplicationConfiguration($app)
     {
         parent::resolveApplicationConfiguration($app);
@@ -16,45 +25,165 @@ protected function resolveApplicationConfiguration($app)
         $app['config']->set('app.url', 'http://absolute-url-resolved-from-request.com');
     }
 
-    public function testPrependsSiteUrl()
+    #[Test]
+    #[DataProvider('tidyProvider')]
+    public function it_can_tidy_urls($url, $expected)
+    {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
+        $this->assertSame($expected, URL::tidy($url));
+
+        URL::enforceTrailingSlashes();
+
+        if (! Str::contains($url, 'external-site.com')) {
+            $expected = preg_replace('/this-site\.com$/', 'this-site.com/', $expected);
+            $expected = str_replace('page', 'page/', $expected);
+        }
+
+        $this->assertSame($expected, URL::tidy($url));
+    }
+
+    public static function tidyProvider()
+    {
+        return [
+            'null case tidies to relative homepage' => [null, '/'],
+            'relative homepage' => ['/', '/'],
+            'relative homepage enforce slash' => ['', '/'],
+
+            'relative route' => ['/page', '/page'],
+            'relative route enforce leading slash' => ['page', '/page'],
+            'relative route normalizes trailing slash' => ['/page/', '/page'],
+            'relative nested route enforce leading slash' => ['foo/page', '/foo/page'],
+            'relative nested route enforce leading slash with query param' => ['foo/page?query', '/foo/page?query'],
+            'relative nested route enforce leading slash with anchor fragment' => ['foo/page#anchor', '/foo/page#anchor'],
+            'relative nested route enforce leading slash with qauery and anchor fragment' => ['foo/page?query#anchor', '/foo/page?query#anchor'],
+            'relative nested route normalizes trailing slash' => ['/foo/page/', '/foo/page'],
+            'relative nested route normalizes trailing slash with query param' => ['/foo/page/?query', '/foo/page?query'],
+            'relative nested route normalizes trailing slash with anchor fragment' => ['/foo/page/#anchor', '/foo/page#anchor'],
+            'relative nested route normalizes trailing slash with query and anchor fragment' => ['/foo/page/?query#anchor', '/foo/page?query#anchor'],
+
+            'absolute url homepage' => ['http://this-site.com', 'http://this-site.com'],
+            'absolute url route' => ['http://this-site.com/page', 'http://this-site.com/page'],
+            'absolute url query' => ['http://this-site.com/page?query', 'http://this-site.com/page?query'],
+            'absolute url anchor' => ['http://this-site.com/page#anchor', 'http://this-site.com/page#anchor'],
+            'absolute url homepage normalizes trailing slash' => ['http://this-site.com/', 'http://this-site.com'],
+            'absolute url route normalizes trailing slash' => ['http://this-site.com/page/', 'http://this-site.com/page'],
+            'absolute url query normalizes trailing slash' => ['http://this-site.com/page/?query', 'http://this-site.com/page?query'],
+            'absolute url anchor normalizes trailing slash' => ['http://this-site.com/page/#anchor', 'http://this-site.com/page#anchor'],
+
+            'fix multiple slashes' => ['////foo///bar////page', '/foo/bar/page'],
+            'fix multiple slashes and enforce leading slash' => ['foo///bar////page', '/foo/bar/page'],
+            'fix multiple slashes and normalize trailing slash' => ['////foo///bar////page///', '/foo/bar/page'],
+            'fixing multiple slashes on absolute url tidies to double slash protocol' => ['http:////this-site.com/foo///bar////page', 'http://this-site.com/foo/bar/page'],
+            'fixing multiple slashes on external url tidies to double slash protocol' => ['http:////external-site.com/foo///bar////page', 'http://external-site.com/foo/bar/page'],
+
+            'external url doesnt touch trailing slash' => ['http://external-site.com/', 'http://external-site.com/'],
+            'external nested url doesnt touch trailing slash' => ['http://external-site.com/page/', 'http://external-site.com/page/'],
+            'external nested url doesnt touch trailing slash or query fragment' => ['http://external-site.com/page/?query#fragment', 'http://external-site.com/page/?query#fragment'],
+        ];
+    }
+
+    #[Test]
+    public function it_can_force_tidy_unconfigured_external_urls()
+    {
+        $this->assertSame('http://external.com/', URL::tidy('http://external.com/'));
+        $this->assertSame('http://external.com', URL::tidy('http://external.com/', force: true));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertSame('http://external.com', URL::tidy('http://external.com'));
+        $this->assertSame('http://external.com/', URL::tidy('http://external.com', force: true));
+    }
+
+    #[Test]
+    public function it_prepends_site_url()
     {
         $this->setSiteValue('en', 'url', 'http://site.com/');
 
-        $this->assertEquals(
-            'http://site.com/foo',
-            URL::prependSiteUrl('/foo')
-        );
+        $this->assertEquals('http://site.com/foo', URL::prependSiteUrl('/foo'));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertEquals('http://site.com/foo/', URL::prependSiteUrl('/foo'));
     }
 
-    public function testPrependsSiteUrlWithController()
+    #[Test]
+    public function it_prepends_site_url_with_controller()
     {
         $this->setSiteValue('en', 'url', 'http://site.com/index.php/');
 
-        $this->assertEquals(
-            'http://site.com/index.php/foo',
-            URL::prependSiteUrl('/foo')
-        );
+        $this->assertEquals('http://site.com/index.php/foo', URL::prependSiteUrl('/foo'));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertEquals('http://site.com/index.php/foo/', URL::prependSiteUrl('/foo'));
     }
 
-    public function testPrependsSiteUrlWithoutController()
+    #[Test]
+    public function it_prepends_site_url_without_controller()
     {
         // Override with what would be used on a normal request.
         request()->server->set('SCRIPT_NAME', '/index.php');
 
         $this->setSiteValue('en', 'url', 'http://site.com/index.php/');
 
-        $this->assertEquals(
-            'http://site.com/foo',
-            URL::prependSiteUrl('/foo', null, false)
-        );
+        $this->assertEquals('http://site.com/foo', URL::prependSiteUrl('/foo', null, false));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertEquals('http://site.com/foo/', URL::prependSiteUrl('/foo', null, false));
     }
 
-    public function testDeterminesExternalUrl()
+    #[Test]
+    public function it_removes_site_url()
     {
         $this->setSiteValue('en', 'url', 'http://this-site.com/');
-        $this->assertTrue(URL::isExternal('http://that-site.com'));
-        $this->assertTrue(URL::isExternal('http://that-site.com/'));
-        $this->assertTrue(URL::isExternal('http://that-site.com/some-slug'));
+
+        $this->assertEquals('/', URL::removeSiteUrl('http://this-site.com'));
+        $this->assertEquals('/foo', URL::removeSiteUrl('http://this-site.com/foo'));
+        $this->assertEquals('/foo', URL::removeSiteUrl('http://this-site.com/foo/'));
+        $this->assertEquals('http://external-site.com/foo/', URL::removeSiteUrl('http://external-site.com/foo/'));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertEquals('/', URL::removeSiteUrl('http://this-site.com/'));
+        $this->assertEquals('/foo/', URL::removeSiteUrl('http://this-site.com/foo'));
+        $this->assertEquals('/foo/', URL::removeSiteUrl('http://this-site.com/foo/'));
+        $this->assertEquals('http://external-site.com/foo', URL::removeSiteUrl('http://external-site.com/foo'));
+    }
+
+    #[Test]
+    public function it_determines_absolute_url()
+    {
+        $this->assertTrue(URL::isAbsolute('http://example.com'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/some-slug'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/some-slug?foo'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/some-slug#anchor'));
+        $this->assertTrue(URL::isAbsolute('http://example.com'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/'));
+        $this->assertTrue(URL::isAbsolute('http://example.com/some-slug'));
+        $this->assertFalse(URL::isAbsolute('/'));
+        $this->assertFalse(URL::isAbsolute('/foo'));
+        $this->assertFalse(URL::isAbsolute('/foo/bar?query'));
+        $this->assertFalse(URL::isAbsolute('foo'));
+        $this->assertFalse(URL::isAbsolute('image.png'));
+        $this->assertFalse(URL::isAbsolute('?query'));
+        $this->assertFalse(URL::isAbsolute('#anchor'));
+        $this->assertFalse(URL::isAbsolute(''));
+        $this->assertFalse(URL::isAbsolute(null));
+    }
+
+    #[Test]
+    public function it_determines_external_url()
+    {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
+        $this->assertTrue(URL::isExternal('http://external-site.com'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug?foo'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug#anchor'));
         $this->assertFalse(URL::isExternal('http://this-site.com'));
         $this->assertFalse(URL::isExternal('http://this-site.com/'));
         $this->assertFalse(URL::isExternal('http://this-site.com/some-slug'));
@@ -64,12 +193,15 @@ public function testDeterminesExternalUrl()
         $this->assertFalse(URL::isExternal(null));
     }
 
-    public function testDeterminesExternalUrlWhenUsingRelativeInConfig()
+    #[Test]
+    public function it_determines_external_url_when_using_relative_in_config()
     {
         $this->setSiteValue('en', 'url', '/');
-        $this->assertTrue(URL::isExternal('http://that-site.com'));
-        $this->assertTrue(URL::isExternal('http://that-site.com/'));
-        $this->assertTrue(URL::isExternal('http://that-site.com/some-slug'));
+        $this->assertTrue(URL::isExternal('http://external-site.com'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug?foo'));
+        $this->assertTrue(URL::isExternal('http://external-site.com/some-slug#anchor'));
         $this->assertFalse(URL::isExternal('http://absolute-url-resolved-from-request.com'));
         $this->assertFalse(URL::isExternal('http://absolute-url-resolved-from-request.com/'));
         $this->assertFalse(URL::isExternal('http://absolute-url-resolved-from-request.com/some-slug'));
@@ -79,6 +211,225 @@ public function testDeterminesExternalUrlWhenUsingRelativeInConfig()
         $this->assertFalse(URL::isExternal(null));
     }
 
+    #[Test]
+    public function it_determines_if_external_url_to_application()
+    {
+        $this->setSites([
+            'first' => ['name' => 'First', 'locale' => 'en_US', 'url' => 'http://this-site.com/'],
+            'third' => ['name' => 'Third', 'locale' => 'en_US', 'url' => 'http://subdomain.this-site.com/'],
+            'second' => ['name' => 'Second', 'locale' => 'fr_FR', 'url' => '/fr/'],
+        ]);
+
+        $this->assertTrue(URL::isExternalToApplication('http://that-site.com'));
+        $this->assertTrue(URL::isExternalToApplication('http://that-site.com/'));
+        $this->assertTrue(URL::isExternalToApplication('http://that-site.com/some-slug'));
+        $this->assertTrue(URL::isExternalToApplication('http://that-site.com/some-slug?foo'));
+        $this->assertTrue(URL::isExternalToApplication('http://that-site.com/some-slug#anchor'));
+
+        $this->assertFalse(URL::isExternalToApplication('http://subdomain.this-site.com'));
+        $this->assertFalse(URL::isExternalToApplication('http://subdomain.this-site.com/'));
+        $this->assertFalse(URL::isExternalToApplication('http://subdomain.this-site.com/some-slug'));
+        $this->assertFalse(URL::isExternalToApplication('http://subdomain.this-site.com/some-slug?foo'));
+        $this->assertFalse(URL::isExternalToApplication('http://subdomain.this-site.com/some-slug#anchor'));
+
+        $this->assertFalse(URL::isExternalToApplication('http://absolute-url-resolved-from-request.com'));
+        $this->assertFalse(URL::isExternalToApplication('http://absolute-url-resolved-from-request.com/'));
+        $this->assertFalse(URL::isExternalToApplication('http://absolute-url-resolved-from-request.com/some-slug'));
+        $this->assertFalse(URL::isExternalToApplication('/foo'));
+        $this->assertFalse(URL::isExternalToApplication('#anchor'));
+        $this->assertFalse(URL::isExternalToApplication(''));
+        $this->assertFalse(URL::isExternalToApplication(null));
+    }
+
+    #[Test]
+    #[DataProvider('assembleProvider')]
+    public function it_can_assemble_urls($segments, $assembled)
+    {
+        $this->assertSame($assembled, URL::assemble(...$segments));
+
+        URL::enforceTrailingSlashes();
+
+        $parts = str($assembled)
+            ->split(pattern: '/([?#])/', flags: PREG_SPLIT_DELIM_CAPTURE)
+            ->all();
+
+        $url = array_shift($parts);
+        $queryAndFragments = implode($parts);
+        $assembledWithTrailingSlash = Str::ensureRight($url, '/').$queryAndFragments;
+
+        $this->assertSame($assembledWithTrailingSlash, URL::assemble(...$segments));
+    }
+
+    public static function assembleProvider()
+    {
+        return [
+            'relative homepage' => [['/'], '/'],
+            'absolute homepage' => [['http://localhost'], 'http://localhost'],
+            'absolute homepage with trailing slash' => [['http://localhost/'], 'http://localhost'],
+
+            'relative route' => [['/', 'foo'], '/foo'],
+            'relative route with trailing slash' => [['/', 'foo/'], '/foo'],
+            'absolute route' => [['http://localhost', 'foo'], 'http://localhost/foo'],
+            'absolute route with trailing slashes' => [['http://localhost/', 'foo/'], 'http://localhost/foo'],
+
+            'relative nested route' => [['/', 'foo', 'bar'], '/foo/bar'],
+            'relative nested route with trailing slashes' => [['/', 'foo/', 'bar/'], '/foo/bar'],
+            'absolute nested route' => [['http://localhost', 'foo', 'bar'], 'http://localhost/foo/bar'],
+            'absolute nested route with trailing slashes' => [['http://localhost/', 'foo/', 'bar/'], 'http://localhost/foo/bar'],
+
+            'with query from relative url' => [['/', 'entries', 'foo', '?alpha'], '/entries/foo?alpha'],
+            'with query from relative url with trailing slashes' => [['/', 'entries/', 'foo/', '?alpha'], '/entries/foo?alpha'],
+            'with query from absolute url' => [['http://localhost', 'entries', 'foo', '?alpha'], 'http://localhost/entries/foo?alpha'],
+            'with query from absolute url with trailing slashes' => [['http://localhost/', 'entries/', 'foo/', '?alpha'], 'http://localhost/entries/foo?alpha'],
+            'with anchor fragment from relative url' => [['/', 'entries', 'foo', '#alpha'], '/entries/foo#alpha'],
+            'with anchor fragment from relative url with trailing slashes' => [['/', 'entries/', 'foo/', '#alpha'], '/entries/foo#alpha'],
+            'with anchor fragment from absolute url' => [['http://localhost', 'entries', 'foo', '#alpha'], 'http://localhost/entries/foo#alpha'],
+            'with anchor fragment from absolute url with trailing slashes' => [['http://localhost/', 'entries/', 'foo/', '#alpha'], 'http://localhost/entries/foo#alpha'],
+            'with query and anchor fragment from relative url' => [['/', 'entries', 'foo', '?alpha#beta'], '/entries/foo?alpha#beta'],
+            'with query and anchor fragment from relative url with trailing slashes' => [['/', 'entries/', 'foo/', '?alpha#beta'], '/entries/foo?alpha#beta'],
+            'with query and anchor fragment from absolute url' => [['http://localhost', 'entries', 'foo', '?alpha#beta'], 'http://localhost/entries/foo?alpha#beta'],
+            'with query and anchor fragment from absolute url with trailing slashes' => [['http://localhost/', 'entries/', 'foo/', '?alpha#beta'], 'http://localhost/entries/foo?alpha#beta'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('slugProvider')]
+    public function it_gets_the_slug_at_the_end_of_a_url($url, $slug)
+    {
+        $this->assertSame($slug, URL::slug($url));
+    }
+
+    public static function slugProvider()
+    {
+        return [
+            'relative homepage should have no slug' => ['/', null],
+            'absolute homepage should have no slug' => ['http://localhost', null],
+            'absolute homepage with trailing slash should have no slug' => ['http://localhost/', null],
+
+            'relative route to slug' => ['/foo', 'foo'],
+            'relative route to slug with trailing slash' => ['/foo/', 'foo'],
+            'absolute route to slug' => ['http://localhost/foo', 'foo'],
+            'absolute route to slug with trailing slash' => ['http://localhost/foo/', 'foo'],
+
+            'relative nested route to slug' => ['/entries/foo', 'foo'],
+            'relative nested route to slug with trailing slash' => ['/entries/foo/', 'foo'],
+            'absolute nested route to slug' => ['http://localhost/entries/foo', 'foo'],
+            'absolute nested route to slug with trailing slash' => ['http://localhost/entries/foo/', 'foo'],
+
+            'removes query from relative url' => ['/entries/foo?alpha', 'foo'],
+            'removes query from relative url with trailing slash' => ['/entries/foo/?alpha', 'foo'],
+            'removes query from absolute url' => ['http://localhost/entries/foo?alpha', 'foo'],
+            'removes query from absolute url with trailing slash' => ['http://localhost/entries/foo/?alpha', 'foo'],
+            'removes anchor fragment from relative url' => ['/entries/foo#alpha', 'foo'],
+            'removes anchor fragment from relative url with trailing slash' => ['/entries/foo/#alpha', 'foo'],
+            'removes anchor fragment from absolute url' => ['http://localhost/entries/foo#alpha', 'foo'],
+            'removes anchor fragment from absolute url with trailing slash' => ['http://localhost/entries/foo/#alpha', 'foo'],
+            'removes query and anchor fragment from relative url' => ['/entries/foo?alpha#beta', 'foo'],
+            'removes query and anchor fragment from relative url with trailing slash' => ['/entries/foo/?alpha#beta', 'foo'],
+            'removes query and anchor fragment from absolute url' => ['http://localhost/entries/foo?alpha#beta', 'foo'],
+            'removes query and anchor fragment from absolute url with trailing slash' => ['http://localhost/entries/foo/?alpha#beta', 'foo'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('replaceSlugProvider')]
+    public function it_replaces_the_slug_at_the_end_of_a_url($url, $replaced)
+    {
+        $this->assertSame($replaced, URL::replaceSlug($url, 'bar'));
+
+        URL::enforceTrailingSlashes();
+
+        $replaced = preg_replace('/localhost$/', 'localhost/', $replaced);
+        $replaced = str_replace('bar', 'bar/', $replaced);
+
+        $this->assertSame($replaced, URL::replaceSlug($url, 'bar'));
+    }
+
+    public static function replaceSlugProvider()
+    {
+        return [
+            'relative homepage should have no slug' => ['/', '/'],
+            'absolute homepage should have no slug' => ['http://localhost', 'http://localhost'],
+            'absolute homepage with trailing slash should have no slug' => ['http://localhost/', 'http://localhost'],
+
+            'relative route to slug' => ['/foo', '/bar'],
+            'relative route to slug with trailing slash' => ['/foo/', '/bar'],
+            'absolute route to slug' => ['http://localhost/foo', 'http://localhost/bar'],
+            'absolute route to slug with trailing slash' => ['http://localhost/foo/', 'http://localhost/bar'],
+
+            'relative nested route to slug' => ['/entries/foo', '/entries/bar'],
+            'relative nested route to slug with trailing slash' => ['/entries/foo/', '/entries/bar'],
+            'absolute nested route to slug' => ['http://localhost/entries/foo', 'http://localhost/entries/bar'],
+            'absolute nested route to slug with trailing slash' => ['http://localhost/entries/bar', 'http://localhost/entries/bar'],
+
+            'removes query from relative url' => ['/entries/foo?alpha', '/entries/bar?alpha'],
+            'removes query from relative url with trailing slash' => ['/entries/foo/?alpha', '/entries/bar?alpha'],
+            'removes query from absolute url' => ['http://localhost/entries/foo?alpha', 'http://localhost/entries/bar?alpha'],
+            'removes query from absolute url with trailing slash' => ['http://localhost/entries/foo/?alpha', 'http://localhost/entries/bar?alpha'],
+            'removes anchor fragment from relative url' => ['/entries/foo#alpha', '/entries/bar#alpha'],
+            'removes anchor fragment from relative url with trailing slash' => ['/entries/foo/#alpha', '/entries/bar#alpha'],
+            'removes anchor fragment from absolute url' => ['http://localhost/entries/foo#alpha', 'http://localhost/entries/bar#alpha'],
+            'removes anchor fragment from absolute url with trailing slash' => ['http://localhost/entries/foo/#alpha', 'http://localhost/entries/bar#alpha'],
+            'removes query and anchor fragment from relative url' => ['/entries/foo?alpha#beta', '/entries/bar?alpha#beta'],
+            'removes query and anchor fragment from relative url with trailing slash' => ['/entries/foo/?alpha#beta', '/entries/bar?alpha#beta'],
+            'removes query and anchor fragment from absolute url' => ['http://localhost/entries/foo?alpha#beta', 'http://localhost/entries/bar?alpha#beta'],
+            'removes query and anchor fragment from absolute url with trailing slash' => ['http://localhost/entries/foo/?alpha#beta', 'http://localhost/entries/bar?alpha#beta'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('parentProvider')]
+    public function it_gets_the_parent_url($child, $parent)
+    {
+        $this->setSites([
+            'en' => ['url' => 'http://this-site.com/', 'locale' => 'en_US', 'name' => 'English'],
+            'fr' => ['url' => 'https://secure-site.com/', 'locale' => 'fr_FR', 'name' => 'French'],
+        ]);
+
+        $this->assertSame($parent, URL::parent($child));
+
+        URL::enforceTrailingSlashes();
+
+        if (! Str::contains($parent, 'external')) {
+            $parent = Str::ensureRight($parent, '/');
+        }
+
+        $this->assertSame($parent, URL::parent($child));
+    }
+
+    public static function parentProvider()
+    {
+        return [
+            'relative homepage to homepage' => ['/', '/'],
+            'absolute homepage to homepage' => ['http://this-site.com', 'http://this-site.com'],
+            'absolute homepage to homepage with trailing slash' => ['http://this-site.com/', 'http://this-site.com'],
+
+            'relative route to parent homepage' => ['/foo', '/'],
+            'relative route to parent homepage with trailing slash' => ['/foo/', '/'],
+            'absolute route to parent homepage' => ['http://this-site.com/foo', 'http://this-site.com'],
+            'absolute route to parent homepage with trailing slash' => ['http://this-site.com/foo/', 'http://this-site.com'],
+
+            'relative nested route to parent homepage' => ['/foo/bar', '/foo'],
+            'relative nested route to parent homepage with trailing slash' => ['/foo/bar/', '/foo'],
+            'absolute nested route to parent homepage' => ['http://this-site.com/foo/bar', 'http://this-site.com/foo'],
+            'absolute nested route to parent homepage with trailing slash' => ['http://this-site.com/foo/bar/', 'http://this-site.com/foo'],
+
+            'removes query from relative url' => ['/?alpha', '/'],
+            'removes query from absolute url' => ['http://this-site.com/?alpha', 'http://this-site.com'],
+            'removes anchor fragment from relative url' => ['/#alpha', '/'],
+            'removes anchor fragment from absolute url' => ['http://this-site.com/#alpha', 'http://this-site.com'],
+            'removes query and anchor fragment from relative url' => ['/?alpha#beta', '/'],
+            'removes query and anchor fragment from absolute url' => ['http://this-site.com/?alpha#beta', 'http://this-site.com'],
+
+            'preserves scheme and host' => ['https://secure-site.com/foo/bar/', 'https://secure-site.com/foo'],
+
+            'preserves lack of trailing slash on external site' => ['https://external-site.com/foo', 'https://external-site.com'],
+            'preserves trailing slash on external site' => ['https://external-site.com/foo/', 'https://external-site.com/'],
+            'preserves lack of trailing slash on external site on nested route' => ['https://external-site.com/foo/bar', 'https://external-site.com/foo'],
+            'preserves trailing slash on external site on nested route' => ['https://external-site.com/foo/bar/', 'https://external-site.com/foo/'],
+        ];
+    }
+
     #[Test]
     #[DataProvider('ancestorProvider')]
     public function it_checks_whether_a_url_is_an_ancestor_of_another($child, $parent, $isAncestor)
@@ -108,136 +459,420 @@ public static function ancestorProvider()
             'directory with trailing slashes to nested directory' => ['/foo/', '/foo/bar', false],
 
             'homepage with query string to homepage' => ['/?baz=qux', '/', false],
-            'directory with query string  to homepage' => ['/foo?baz=qux', '/', true],
-            'nested directory with query string  to homepage' => ['/foo/bar?baz=qux', '/', true],
-            'nested directory with query string  to directory' => ['/foo/bar?baz=qux', '/foo', true],
-            'directory with query string  to nested directory' => ['/foo?baz=qux', '/foo/bar', false],
-            'homepage with query string  to nested directory' => ['/?baz=qux', '/foo', false],
+            'directory with query string to homepage' => ['/foo?baz=qux', '/', true],
+            'nested directory with query string to homepage' => ['/foo/bar?baz=qux', '/', true],
+            'nested directory with query string to directory' => ['/foo/bar?baz=qux', '/foo', true],
+            'directory with query string to nested directory' => ['/foo?baz=qux', '/foo/bar', false],
+            'homepage with query string to nested directory' => ['/?baz=qux', '/foo', false],
+
+            'homepage with query string to homepage with query string' => ['/?baz=qux', '/?alpha=true', false],
+            'directory with query string to homepage with query string' => ['/foo?baz=qux', '/?alpha=true', true],
+            'nested directory with query string to homepage with query string' => ['/foo/bar?baz=qux', '/?alpha=true', true],
+            'nested directory with query string to directory with query string' => ['/foo/bar?baz=qux', '/foo?alpha=true', true],
+            'directory with query string to nested directory with query string' => ['/foo?baz=qux', '/foo/bar?alpha=true', false],
+            'homepage with query string to nested directory with query string' => ['/?baz=qux', '/foo?alpha=true', false],
+
+            'homepage with anchor fragment to homepage with anchor fragment' => ['/#alpha', '/#beta', false],
+            'directory with anchor fragment to homepage with anchor fragment' => ['/foo#alpha', '/#beta', true],
+            'nested directory with anchor fragment to homepage with anchor fragment' => ['/foo/bar#alpha', '/#beta', true],
+            'nested directory with anchor fragment to directory with anchor fragment' => ['/foo/bar#alpha', '/foo#beta', true],
+            'directory with anchor fragment to nested directory with anchor fragment' => ['/foo#alpha', '/foo/bar#beta', false],
+            'homepage with anchor fragment to nested directory with anchor fragment' => ['/#alpha', '/foo#beta', false],
         ];
     }
 
-    #[Test]
-    public function gets_site_url()
-    {
-        $this->assertEquals('http://absolute-url-resolved-from-request.com/', URL::getSiteUrl());
-
-        \Illuminate\Support\Facades\URL::forceScheme('https');
-        $this->assertEquals('https://absolute-url-resolved-from-request.com/', URL::getSiteUrl());
-
-        \Illuminate\Support\Facades\URL::forceScheme('http');
-        $this->assertEquals('http://absolute-url-resolved-from-request.com/', URL::getSiteUrl());
-    }
-
     #[Test]
     #[DataProvider('absoluteProvider')]
     public function it_makes_urls_absolute($url, $expected, $forceScheme = false)
     {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
         if ($forceScheme) {
             \Illuminate\Support\Facades\URL::forceScheme($forceScheme);
         }
 
         $this->assertSame($expected, URL::makeAbsolute($url));
+
+        URL::enforceTrailingSlashes();
+
+        $expected = Str::contains($url, 'external-site.com')
+            ? $url
+            : Str::ensureRight($expected, '/');
+
+        $this->assertSame($expected, URL::makeAbsolute($url));
     }
 
     public static function absoluteProvider()
     {
         return [
-            ['http://example.com', 'http://example.com'],
-            ['http://example.com/', 'http://example.com/'],
-            ['/', 'http://absolute-url-resolved-from-request.com/'],
-            ['/foo', 'http://absolute-url-resolved-from-request.com/foo'],
-            ['/foo/', 'http://absolute-url-resolved-from-request.com/foo/'],
-
-            ['http://example.com', 'http://example.com', 'https'], // absolute url provided, so scheme is left alone.
-            ['http://example.com/', 'http://example.com/', 'https'], // absolute url provided, so scheme is left alone.
-            ['/', 'https://absolute-url-resolved-from-request.com/', 'https'],
-            ['/foo', 'https://absolute-url-resolved-from-request.com/foo', 'https'],
-            ['/foo/', 'https://absolute-url-resolved-from-request.com/foo/', 'https'],
-
-            ['https://example.com', 'https://example.com', 'http'], // absolute url provided, so scheme is left alone.
-            ['https://example.com/', 'https://example.com/', 'http'], // absolute url provided, so scheme is left alone.
-            ['/', 'http://absolute-url-resolved-from-request.com/', 'http'],
-            ['/foo', 'http://absolute-url-resolved-from-request.com/foo', 'http'],
-            ['/foo/', 'http://absolute-url-resolved-from-request.com/foo/', 'http'],
+            'absolute homepage' => ['/', 'http://absolute-url-resolved-from-request.com'],
+            'absolute route' => ['/foo', 'http://absolute-url-resolved-from-request.com/foo'],
+            'absolute route without leading slash' => ['foo', 'http://absolute-url-resolved-from-request.com/foo'],
+            'absolute route with trailing slash' => ['/foo/', 'http://absolute-url-resolved-from-request.com/foo'],
+            'already absolute request url but normalize trailing slash' => ['http://absolute-url-resolved-from-request.com/foo/', 'http://absolute-url-resolved-from-request.com/foo'],
+            'already absolute site url but normalize trailing slash' => ['http://this-site.com/foo/', 'http://this-site.com/foo'],
+            'leave external url without trailing slash' => ['http://external-site.com', 'http://external-site.com'],
+            'leave external url with trailing slash' => ['http://external-site.com/', 'http://external-site.com/'],
+
+            'absolute homepage and force https scheme' => ['/', 'https://absolute-url-resolved-from-request.com', 'https'],
+            'absolute route and force https scheme' => ['/foo', 'https://absolute-url-resolved-from-request.com/foo', 'https'],
+            'absolute route without leading slash and force https scheme' => ['foo', 'https://absolute-url-resolved-from-request.com/foo', 'https'],
+            'absolute route with trailing slash and force https scheme' => ['/foo/', 'https://absolute-url-resolved-from-request.com/foo', 'https'],
+            'leave external url without trailing slash and force https scheme' => ['http://external-site.com', 'http://external-site.com', 'https'],
+            'leave external url with trailing slash and force https scheme' => ['http://external-site.com/', 'http://external-site.com/', 'https'],
+
+            'absolute homepage and force http scheme' => ['/', 'http://absolute-url-resolved-from-request.com', 'http'],
+            'absolute route and force http scheme' => ['/foo', 'http://absolute-url-resolved-from-request.com/foo', 'http'],
+            'absolute route without leading slash and force http scheme' => ['foo', 'http://absolute-url-resolved-from-request.com/foo', 'http'],
+            'absolute route with trailing slash and force http scheme' => ['/foo/', 'http://absolute-url-resolved-from-request.com/foo', 'http'],
+            'leave external url without trailing slash and force http scheme' => ['https://external-site.com', 'https://external-site.com', 'http'],
+            'leave external url with trailing slash and force http scheme' => ['https://external-site.com/', 'https://external-site.com/', 'http'],
         ];
     }
 
     #[Test]
     #[DataProvider('relativeProvider')]
-    public function makes_urls_relative($url, $expected)
+    public function it_makes_urls_relative($url, $expected)
     {
         $this->assertSame($expected, URL::makeRelative($url));
+
+        URL::enforceTrailingSlashes();
+
+        $expected = str_replace('page', 'page/', $expected);
+
+        $this->assertSame($expected, URL::makeRelative($url));
     }
 
     public static function relativeProvider()
     {
         return [
-            ['http://example.com', '/'],
-            ['http://example.com/', '/'],
-            ['http://example.com/foo', '/foo'],
-            ['http://example.com/foo/', '/foo/'],
-            ['http://example.com/foo/bar', '/foo/bar'],
-            ['http://example.com/foo/bar/', '/foo/bar/'],
-            ['/', '/'],
-            ['/foo', '/foo'],
-            ['/foo/', '/foo/'],
-            ['/foo/bar', '/foo/bar'],
-            ['/foo/bar/', '/foo/bar/'],
-
-            ['http://example.com?bar=baz', '/?bar=baz'],
-            ['http://example.com/?bar=baz', '/?bar=baz'],
-            ['http://example.com/foo?bar=baz', '/foo?bar=baz'],
-            ['http://example.com/foo/?bar=baz', '/foo/?bar=baz'],
-            ['http://example.com/foo/bar?bar=baz', '/foo/bar?bar=baz'],
-            ['http://example.com/foo/bar/?bar=baz', '/foo/bar/?bar=baz'],
-            ['/?bar=baz', '/?bar=baz'],
-            ['/foo?bar=baz', '/foo?bar=baz'],
-            ['/foo/?bar=baz', '/foo/?bar=baz'],
-            ['/foo/bar?bar=baz', '/foo/bar?bar=baz'],
-            ['/foo/bar/?bar=baz', '/foo/bar/?bar=baz'],
-
-            ['http://example.com#fragment', '/#fragment'],
-            ['http://example.com/#fragment', '/#fragment'],
-            ['http://example.com/foo#fragment', '/foo#fragment'],
-            ['http://example.com/foo/#fragment', '/foo/#fragment'],
-            ['http://example.com/foo/bar#fragment', '/foo/bar#fragment'],
-            ['http://example.com/foo/bar/#fragment', '/foo/bar/#fragment'],
-            ['/#fragment', '/#fragment'],
-            ['/foo#fragment', '/foo#fragment'],
-            ['/foo/#fragment', '/foo/#fragment'],
-            ['/foo/bar#fragment', '/foo/bar#fragment'],
-            ['/foo/bar/#fragment', '/foo/bar/#fragment'],
-
-            ['http://example.com?bar=baz#fragment', '/?bar=baz#fragment'],
-            ['http://example.com/?bar=baz#fragment', '/?bar=baz#fragment'],
-            ['http://example.com/foo?bar=baz#fragment', '/foo?bar=baz#fragment'],
-            ['http://example.com/foo/?bar=baz#fragment', '/foo/?bar=baz#fragment'],
-            ['http://example.com/foo/bar?bar=baz#fragment', '/foo/bar?bar=baz#fragment'],
-            ['http://example.com/foo/bar/?bar=baz#fragment', '/foo/bar/?bar=baz#fragment'],
-            ['/?bar=baz#fragment', '/?bar=baz#fragment'],
-            ['/foo?bar=baz#fragment', '/foo?bar=baz#fragment'],
-            ['/foo/?bar=baz#fragment', '/foo/?bar=baz#fragment'],
-            ['/foo/bar?bar=baz#fragment', '/foo/bar?bar=baz#fragment'],
-            ['/foo/bar/?bar=baz#fragment', '/foo/bar/?bar=baz#fragment'],
+            'null case tidies to homepage' => [null, '/'],
+
+            'homepage without trailing slash' => ['http://example.com', '/'],
+            'homepage with trailing slash' => ['http://example.com/', '/'],
+            'route without trailing slash' => ['http://example.com/page', '/page'],
+            'route with trailing slash' => ['http://example.com/page/', '/page'],
+            'nested route without trailing slash' => ['http://example.com/foo/page', '/foo/page'],
+            'nested route with trailing slash' => ['http://example.com/foo/page/', '/foo/page'],
+            'already relative homepage' => ['/', '/'],
+            'already relative route without trailing slash' => ['/page', '/page'],
+            'already relative route with trailing slash' => ['/page/', '/page'],
+            'already relative route without leading slash' => ['page', '/page'],
+            'already relative nested route without trailing slash' => ['/foo/page', '/foo/page'],
+            'already relative nested route with trailing slash' => ['/foo/page/', '/foo/page'],
+            'already relative nested route without leading slash' => ['foo/page', '/foo/page'],
+
+            'homepage without trailing slash and query param' => ['http://example.com?bar=baz', '/?bar=baz'],
+            'homepage with trailing slash and query param' => ['http://example.com/?bar=baz', '/?bar=baz'],
+            'route without trailing slash and query param' => ['http://example.com/page?bar=baz', '/page?bar=baz'],
+            'route with trailing slash and query param' => ['http://example.com/page/?bar=baz', '/page?bar=baz'],
+            'nested route without trailing slash and query param' => ['http://example.com/foo/page?bar=baz', '/foo/page?bar=baz'],
+            'nested route with trailing slash and query param' => ['http://example.com/foo/page/?bar=baz', '/foo/page?bar=baz'],
+            'already relative homepage with query param' => ['/?bar=baz', '/?bar=baz'],
+            'already relative route without trailing slash and query param' => ['/page?bar=baz', '/page?bar=baz'],
+            'already relative route with trailing slash and query param' => ['/page/?bar=baz', '/page?bar=baz'],
+            'already relative nested route without trailing slash and query param' => ['/foo/page?bar=baz', '/foo/page?bar=baz'],
+            'already relative nested route with trailing slash and query param' => ['/foo/page/?bar=baz', '/foo/page?bar=baz'],
+
+            'homepage without trailing slash and anchor fragment' => ['http://example.com#fragment', '/#fragment'],
+            'homepage with trailing slash and anchor fragment' => ['http://example.com/#fragment', '/#fragment'],
+            'route without trailing slash and anchor fragment' => ['http://example.com/page#fragment', '/page#fragment'],
+            'route with trailing slash and anchor fragment' => ['http://example.com/page/#fragment', '/page#fragment'],
+            'nested route without trailing slash and anchor fragment' => ['http://example.com/foo/page#fragment', '/foo/page#fragment'],
+            'nested route with trailing slash and anchor fragment' => ['http://example.com/foo/page/#fragment', '/foo/page#fragment'],
+            'already relative homepage with anchor fragment' => ['/#fragment', '/#fragment'],
+            'already relative route without trailing slash and anchor fragment' => ['/page#fragment', '/page#fragment'],
+            'already relative route with trailing slash and anchor fragment' => ['/page/#fragment', '/page#fragment'],
+            'already relative nested route without trailing slash and anchor fragment' => ['/foo/page#fragment', '/foo/page#fragment'],
+            'already relative nested route with trailing slash and anchor fragment' => ['/foo/page/#fragment', '/foo/page#fragment'],
+
+            'homepage without trailing slash and query with anchor fragment' => ['http://example.com?bar=baz#fragment', '/?bar=baz#fragment'],
+            'homepage with trailing slash and query with anchor fragment' => ['http://example.com/?bar=baz#fragment', '/?bar=baz#fragment'],
+            'route without trailing slash and query with anchor fragment' => ['http://example.com/page?bar=baz#fragment', '/page?bar=baz#fragment'],
+            'route with trailing slash and query with anchor fragment' => ['http://example.com/page/?bar=baz#fragment', '/page?bar=baz#fragment'],
+            'nested route without trailing slash and query with anchor fragment' => ['http://example.com/foo/page?bar=baz#fragment', '/foo/page?bar=baz#fragment'],
+            'nested route with trailing slash and query with anchor fragment' => ['http://example.com/foo/page/?bar=baz#fragment', '/foo/page?bar=baz#fragment'],
+            'already relative homepage with query and anchor fragment' => ['/?bar=baz#fragment', '/?bar=baz#fragment'],
+            'already relative route without trailing slash and query with anchor fragment' => ['/page?bar=baz#fragment', '/page?bar=baz#fragment'],
+            'already relative route with trailing slash and query with anchor fragment' => ['/page/?bar=baz#fragment', '/page?bar=baz#fragment'],
+            'already relative nested route without trailing slash and query with anchor fragment' => ['/foo/page?bar=baz#fragment', '/foo/page?bar=baz#fragment'],
+            'already relative nested route with trailing slash and query with anchor fragment' => ['/foo/page/?bar=baz#fragment', '/foo/page?bar=baz#fragment'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('encodeProvider')]
+    public function it_can_encode_urls($url, $expected)
+    {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
+        $this->assertSame($expected, URL::encode($url));
+
+        URL::enforceTrailingSlashes();
+
+        $expected = str_replace('page', 'page/', $expected);
+
+        $this->assertSame($expected, URL::encode($url));
+    }
+
+    public static function encodeProvider()
+    {
+        $encodable = '\'"$^<>[](){}';
+        $encoded = '%27%22%24%5E%3C%3E%5B%5D%28%29%7B%7D';
+
+        return [
+            'null case tidies to relative homepage' => [null, '/'],
+            'relative homepage' => ['/', '/'],
+            'relative homepage enforce slash' => ['', '/'],
+
+            'relative route with encodable' => ["/{$encodable}/page", "/{$encoded}/page"],
+            'relative route with encodable enforce leading slash' => ["{$encodable}/page", "/{$encoded}/page"],
+            'relative route with encodable normalize trailing slash' => ["/{$encodable}/page/", "/{$encoded}/page"],
+
+            'doesnt encode specific characters' => ['http://this-site.com/page?param&characters=-/@:;,+!*|%#fragment', 'http://this-site.com/page?param&characters=-/@:;,+!*|%#fragment'],
+            'doesnt encode specific characters but still can normalize trailing slash' => ['http://this-site.com/page/?param&characters=-/@:;,+!*|%#fragment', 'http://this-site.com/page?param&characters=-/@:;,+!*|%#fragment'],
+
+            'absolute external url doesnt enforce trailing slash' => ['http://external-site.com.com/foo?param&characters=-/@:;,+!*|%#fragment', 'http://external-site.com.com/foo?param&characters=-/@:;,+!*|%#fragment'],
+            'absolute external url doesnt remove trailing slash' => ['http://external-site.com.com/foo/?param&characters=-/@:;,+!*|%#fragment', 'http://external-site.com.com/foo/?param&characters=-/@:;,+!*|%#fragment'],
+        ];
+    }
+
+    #[Test]
+    public function it_can_get_gravatar_image_urls_from_email()
+    {
+        $hashGravatarEmail = function ($email) {
+            return e(md5(strtolower($email)));
+        };
+
+        $this->assertSame(
+            'https://www.gravatar.com/avatar/'.$hashGravatarEmail('Jeremy@pearl.jam'),
+            URL::gravatar('Jeremy@pearl.jam'),
+        );
+
+        $this->assertSame(
+            'https://www.gravatar.com/avatar/'.$hashGravatarEmail('Jeremy@pearl.jam').'?s=32',
+            URL::gravatar('Jeremy@pearl.jam', 32),
+        );
+    }
+
+    #[Test]
+    #[DataProvider('removeQueryAndFragmentProvider')]
+    public function it_can_remove_query_and_fragment($url, $expected)
+    {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
+        $this->assertSame($expected, URL::removeQueryAndFragment($url));
+
+        URL::enforceTrailingSlashes();
+
+        $expected = preg_replace('/this-site\.com$/', 'this-site.com/', $expected);
+        $expected = str_replace('page', 'page/', $expected);
+
+        $this->assertSame($expected, URL::removeQueryAndFragment($url));
+    }
+
+    public static function removeQueryAndFragmentProvider()
+    {
+        return [
+            'null case tidies to relative homepage' => [null, '/'],
+
+            'relative homepage with query param' => ['/?query', '/'],
+            'relative homepage with anchor fragment' => ['/#anchor', '/'],
+            'relative homepage with query and anchor fragment' => ['/?query#anchor', '/'],
+            'relative homepage enforce slash with query param' => ['?query', '/'],
+            'relative homepage enforce slash with anchor fragment' => ['#anchor', '/'],
+            'relative homepage enforce slash with query and anchor fragment' => ['?query#anchor', '/'],
+
+            'relative route enforce leading slash with query param' => ['foo/page?query', '/foo/page'],
+            'relative route enforce leading slash with anchor fragment' => ['foo/page#anchor', '/foo/page'],
+            'relative route enforce leading slash with query and anchor fragment' => ['foo/page?query#anchor', '/foo/page'],
+            'relative route normalizes trailing slash with query param' => ['/foo/page/?query', '/foo/page'],
+            'relative route normalizes trailing slash with anchor fragment' => ['/foo/page/#anchor', '/foo/page'],
+            'relative route normalizes trailing slash with query and anchor fragment' => ['/foo/page/?query#anchor', '/foo/page'],
+
+            'absolute url query' => ['http://this-site.com/page?query', 'http://this-site.com/page'],
+            'absolute url anchor' => ['http://this-site.com/page#anchor', 'http://this-site.com/page'],
+            'absolute url query normalizes trailing slash' => ['http://this-site.com/page/?query', 'http://this-site.com/page'],
+            'absolute url anchor normalizes trailing slash' => ['http://this-site.com/page/#anchor', 'http://this-site.com/page'],
+
+            'absolute external url query doesnt enforce trailing slash' => ['http://external-site.com/foo?query', 'http://external-site.com/foo'],
+            'absolute external url anchor doesnt enforce trailing slash' => ['http://external-site.com/foo#anchor', 'http://external-site.com/foo'],
+            'absolute external url query doesnt remove trailing slash' => ['http://external-site.com/foo/?query', 'http://external-site.com/foo/'],
+            'absolute external url anchor doesnt remove trailing slash' => ['http://external-site.com/foo/#anchor', 'http://external-site.com/foo/'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('enforceTrailingSlashesProvider')]
+    public function enforces_trailing_slashes($url, $expected)
+    {
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertSame($expected, URL::tidy($url));
+    }
+
+    public static function enforceTrailingSlashesProvider()
+    {
+        return [
+            'null case always enforces slash' => [null, '/'],
+            'empty string always enforces slash' => ['', '/'],
+            'relative homepage always enforces slash' => ['/', '/'],
+
+            'homepage without leading slash and query param enforces slash' => ['?query', '/?query'],
+            'homepage without leading slash with anchor fragment enforces slash' => ['#anchor', '/#anchor'],
+            'homepage without leading slash and both query and anchor enforces slash' => ['?query#anchor', '/?query#anchor'],
+
+            'homepage with leading slash and query param enforces slash' => ['/?query', '/?query'],
+            'homepage with leading slash with anchor fragment enforces slash' => ['/#anchor', '/#anchor'],
+            'homepage with leading slash and both query and anchor enforces slash' => ['/?query#anchor', '/?query#anchor'],
+
+            'relative route with leading slash enforces trailing slash' => ['/about', '/about/'],
+            'relative route with leading slash and query param enforces trailing slash' => ['/about?query', '/about/?query'],
+            'relative route with leading slash and anchor fragment enforces trailing slash' => ['/about#anchor', '/about/#anchor'],
+            'relative route with leading slash and both query and anchor enforces trailing slash' => ['/about?query#anchor', '/about/?query#anchor'],
+
+            'relative route without leading slash enforces trailing slash' => ['about', '/about/'],
+            'relative route without leading slash and query param enforces trailing slash' => ['about?query', '/about/?query'],
+            'relative route without leading slash and anchor fragment enforces trailing slash' => ['about#anchor', '/about/#anchor'],
+            'relative route without leading slash and both query and anchor enforces trailing slash' => ['about?query#anchor', '/about/?query#anchor'],
+
+            'relative route no change needed' => ['/about/', '/about/'],
+            'relative route with query param no change needed' => ['/about/?query', '/about/?query'],
+            'relative route with anchor fragment no change needed' => ['/about/#anchor', '/about/#anchor'],
+            'relative route with both query and anchor no change needed' => ['/about/?query#anchor', '/about/?query#anchor'],
+
+            'absolute homepage without trailing slash enforces trailing slash' => ['http://this-site.com', 'http://this-site.com/'],
+            'absolute homepage without trailing slash and query param enforces trailing slash' => ['http://this-site.com?query', 'http://this-site.com/?query'],
+            'absolute homepage without trailing slash and anchor fragment enforces trailing slash' => ['http://this-site.com#anchor', 'http://this-site.com/#anchor'],
+            'absolute homepage without trailing slash and both query and anchor enforces trailing slash' => ['http://this-site.com?query#anchor', 'http://this-site.com/?query#anchor'],
+
+            'absolute homepage with trailing slash no change needed' => ['http://this-site.com/', 'http://this-site.com/'],
+            'absolute homepage with trailing slash and query param no change needed' => ['http://this-site.com/?query', 'http://this-site.com/?query'],
+            'absolute homepage with trailing slash and anchor fragment no change needed' => ['http://this-site.com/#anchor', 'http://this-site.com/#anchor'],
+            'absolute homepage with trailing slash and both query and anchor no change needed' => ['http://this-site.com/?query#anchor', 'http://this-site.com/?query#anchor'],
+
+            'absolute route without trailing slash enforces trailing slash' => ['http://this-site.com/about', 'http://this-site.com/about/'],
+            'absolute route without trailing slash and query param enforces trailing slash' => ['http://this-site.com/about?query', 'http://this-site.com/about/?query'],
+            'absolute route without trailing slash and anchor fragment enforces trailing slash' => ['http://this-site.com/about#anchor', 'http://this-site.com/about/#anchor'],
+            'absolute route without trailing slash and both query and anchor enforces trailing slash' => ['http://this-site.com/about?query#anchor', 'http://this-site.com/about/?query#anchor'],
+
+            'absolute route with trailing slash no change needed' => ['http://this-site.com/about/', 'http://this-site.com/about/'],
+            'absolute route with trailing slash and query param no change needed' => ['http://this-site.com/about/?query', 'http://this-site.com/about/?query'],
+            'absolute route with trailing slash and anchor fragment no change needed' => ['http://this-site.com/about/#anchor', 'http://this-site.com/about/#anchor'],
+            'absolute route with trailing slash and both query and anchor no change needed' => ['http://this-site.com/about/?query#anchor', 'http://this-site.com/about/?query#anchor'],
+
+            'doesnt enforce on external site homepage' => ['http://external-site.com', 'http://external-site.com'],
+            'doesnt enforce on external site route' => ['http://external-site.com/about', 'http://external-site.com/about'],
+            'doesnt enforce on external site route with query param' => ['http://external-site.com/about?query', 'http://external-site.com/about?query'],
+            'doesnt enforce on external site route with anchor fragment' => ['http://external-site.com/about#anchor', 'http://external-site.com/about#anchor'],
+            'doesnt enforce on external site route with query and anchor' => ['http://external-site.com/about?query#anchor', 'http://external-site.com/about?query#anchor'],
         ];
     }
 
     #[Test]
-    public function it_can_remove_query_and_fragment()
+    #[DataProvider('removeTrailingSlashesProvider')]
+    public function removes_trailing_slashes($url, $expected)
     {
-        $this->assertEquals('https://example.com', URL::removeQueryAndFragment('https://example.com?query'));
-        $this->assertEquals('https://example.com', URL::removeQueryAndFragment('https://example.com#anchor'));
-        $this->assertEquals('https://example.com', URL::removeQueryAndFragment('https://example.com?foo=bar&baz=qux'));
-        $this->assertEquals('https://example.com', URL::removeQueryAndFragment('https://example.com?foo=bar&baz=qux#anchor'));
+        $this->setSiteValue('en', 'url', 'http://this-site.com/');
 
-        $this->assertEquals('https://example.com/', URL::removeQueryAndFragment('https://example.com/?query'));
-        $this->assertEquals('https://example.com/', URL::removeQueryAndFragment('https://example.com/#anchor'));
-        $this->assertEquals('https://example.com/', URL::removeQueryAndFragment('https://example.com/?foo=bar&baz=qux'));
-        $this->assertEquals('https://example.com/', URL::removeQueryAndFragment('https://example.com/?foo=bar&baz=qux#anchor'));
+        $this->assertSame($expected, URL::tidy($url));
+    }
 
-        $this->assertEquals('https://example.com/about', URL::removeQueryAndFragment('https://example.com/about?query'));
-        $this->assertEquals('https://example.com/about', URL::removeQueryAndFragment('https://example.com/about#anchor'));
-        $this->assertEquals('https://example.com/about', URL::removeQueryAndFragment('https://example.com/about?foo=bar&baz=qux'));
-        $this->assertEquals('https://example.com/about', URL::removeQueryAndFragment('https://example.com/about?foo=bar&baz=qux#anchor'));
+    public static function removeTrailingSlashesProvider()
+    {
+        return [
+            'null case always enforces slash' => [null, '/'],
+            'empty string always enforces slash' => ['', '/'],
+            'relative homepage always enforces slash' => ['/', '/'],
+
+            'homepage without leading slash and query param enforces slash' => ['?query', '/?query'],
+            'homepage without leading slash with anchor fragment enforces slash' => ['#anchor', '/#anchor'],
+            'homepage without leading slash and both query and anchor enforces slash' => ['?query#anchor', '/?query#anchor'],
+
+            'homepage with leading slash and query param enforces slash' => ['/?query', '/?query'],
+            'homepage with leading slash with anchor fragment enforces slash' => ['/#anchor', '/#anchor'],
+            'homepage with leading slash and both query and anchor enforces slash' => ['/?query#anchor', '/?query#anchor'],
+
+            'relative route no change needed' => ['/about', '/about'],
+            'relative route with query param no change needed' => ['/about?query', '/about?query'],
+            'relative route with anchor fragment no change needed' => ['/about#anchor', '/about#anchor'],
+            'relative route with both query and anchor no change needed' => ['/about?query#anchor', '/about?query#anchor'],
+
+            'relative route without leading slash removes trailing slash' => ['about/', '/about'],
+            'relative route without leading slash and query param removes trailing slash' => ['about/?query', '/about?query'],
+            'relative route without leading slash and anchor fragment removes trailing slash' => ['about/#anchor', '/about#anchor'],
+            'relative route without leading slash and both query and anchor removes trailing slash' => ['about/?query#anchor', '/about?query#anchor'],
+
+            'relative route with leading slash removes trailing slash' => ['/about/', '/about'],
+            'relative route with leading slash and query param removes trailing slash' => ['/about/?query', '/about?query'],
+            'relative route with leading slash and anchor fragment removes trailing slash' => ['/about/#anchor', '/about#anchor'],
+            'relative route with leading slash and both query and anchor removes trailing slash' => ['/about/?query#anchor', '/about?query#anchor'],
+
+            'absolute homepage without trailing slash no change needed' => ['http://this-site.com', 'http://this-site.com'],
+            'absolute homepage without trailing slash and query param no change needed' => ['http://this-site.com?query', 'http://this-site.com?query'],
+            'absolute homepage without trailing slash and anchor fragment no change needed' => ['http://this-site.com#anchor', 'http://this-site.com#anchor'],
+            'absolute homepage without trailing slash and both query and anchor no change needed' => ['http://this-site.com?query#anchor', 'http://this-site.com?query#anchor'],
+
+            'absolute homepage with trailing slash removes trailing slash' => ['http://this-site.com/', 'http://this-site.com'],
+            'absolute homepage with trailing slash and query param removes trailing slash' => ['http://this-site.com/?query', 'http://this-site.com?query'],
+            'absolute homepage with trailing slash and anchor fragment removes trailing slash' => ['http://this-site.com/#anchor', 'http://this-site.com#anchor'],
+            'absolute homepage with trailing slash and both query and anchor removes trailing slash' => ['http://this-site.com/?query#anchor', 'http://this-site.com?query#anchor'],
+
+            'absolute route without trailing slash no change needed' => ['http://this-site.com/about', 'http://this-site.com/about'],
+            'absolute route without trailing slash and query param no change needed' => ['http://this-site.com/about?query', 'http://this-site.com/about?query'],
+            'absolute route without trailing slash and anchor fragment no change needed' => ['http://this-site.com/about#anchor', 'http://this-site.com/about#anchor'],
+            'absolute route without trailing slash and both query and anchor no change needed' => ['http://this-site.com/about?query#anchor', 'http://this-site.com/about?query#anchor'],
+
+            'absolute route with trailing slash removes trailing slash' => ['http://this-site.com/about/', 'http://this-site.com/about'],
+            'absolute route with trailing slash and query param removes trailing slash' => ['http://this-site.com/about/?query', 'http://this-site.com/about?query'],
+            'absolute route with trailing slash and anchor fragment removes trailing slash' => ['http://this-site.com/about/#anchor', 'http://this-site.com/about#anchor'],
+            'absolute route with trailing slash and both query and anchor removes trailing slash' => ['http://this-site.com/about/?query#anchor', 'http://this-site.com/about?query#anchor'],
+
+            'doesnt remove on external site homepage' => ['http://external-site.com/', 'http://external-site.com/'],
+            'doesnt remove on external site route' => ['http://external-site.com/about/', 'http://external-site.com/about/'],
+            'doesnt remove on external site route with query param' => ['http://external-site.com/about/?query', 'http://external-site.com/about/?query'],
+            'doesnt remove on external site route with anchor fragment' => ['http://external-site.com/about/#anchor', 'http://external-site.com/about/#anchor'],
+            'doesnt remove on external site route with query and anchor' => ['http://external-site.com/about/?query#anchor', 'http://external-site.com/about/?query#anchor'],
+        ];
+    }
+
+    #[Test]
+    public function it_can_configure_and_unconfigure_enforcing_of_trailing_slashes()
+    {
+        $this->assertSame('http://localhost?query', URL::tidy('http://localhost/?query'));
+        $this->assertSame('http://localhost/foo', URL::parent('http://localhost/foo/bar/'));
+        $this->assertSame('http://localhost/foo', URL::prependSiteUrl('/foo/'));
+        $this->assertSame('/foo', URL::removeSiteUrl('http://localhost/foo/'));
+        $this->assertSame('http://absolute-url-resolved-from-request.com/foo?query', URL::makeAbsolute('/foo/?query'));
+        $this->assertSame('/foo?query', URL::makeRelative('http://localhost/foo/?query'));
+        $this->assertSame('http://localhost/bar?query', URL::assemble('http://localhost', 'bar', '?query'));
+        $this->assertSame('http://localhost/bar', URL::replaceSlug('http://localhost/foo/', 'bar'));
+        $this->assertSame('http://localhost/foo%24bar', URL::encode('http://localhost/foo$bar'));
+
+        URL::enforceTrailingSlashes();
+
+        $this->assertSame('http://localhost/?query', URL::tidy('http://localhost?query'));
+        $this->assertSame('http://localhost/foo/', URL::parent('http://localhost/foo/bar'));
+        $this->assertSame('http://localhost/foo/', URL::prependSiteUrl('/foo'));
+        $this->assertSame('/foo/', URL::removeSiteUrl('http://localhost/foo'));
+        $this->assertSame('http://absolute-url-resolved-from-request.com/foo/?query', URL::makeAbsolute('/foo?query'));
+        $this->assertSame('/foo/?query', URL::makeRelative('http://localhost/foo?query'));
+        $this->assertSame('http://localhost/bar/?query', URL::assemble('http://localhost', 'bar', '?query'));
+        $this->assertSame('http://localhost/bar/', URL::replaceSlug('http://localhost/foo', 'bar'));
+        $this->assertSame('http://localhost/foo%24bar/', URL::encode('http://localhost/foo$bar'));
+
+        URL::enforceTrailingSlashes(false);
+
+        $this->assertSame('http://localhost?query', URL::tidy('http://localhost/?query'));
+        $this->assertSame('http://localhost/foo', URL::parent('http://localhost/foo/bar/'));
+        $this->assertSame('http://localhost/foo', URL::prependSiteUrl('/foo/'));
+        $this->assertSame('/foo', URL::removeSiteUrl('http://localhost/foo/'));
+        $this->assertSame('http://absolute-url-resolved-from-request.com/foo?query', URL::makeAbsolute('/foo/?query'));
+        $this->assertSame('/foo?query', URL::makeRelative('http://localhost/foo/?query'));
+        $this->assertSame('http://localhost/bar?query', URL::assemble('http://localhost', 'bar', '?query'));
+        $this->assertSame('http://localhost/bar', URL::replaceSlug('http://localhost/foo/', 'bar'));
+        $this->assertSame('http://localhost/foo%24bar', URL::encode('http://localhost/foo$bar'));
     }
 }
diff --git a/tests/Imaging/StaticUrlBuilderTest.php b/tests/Imaging/StaticUrlBuilderTest.php
index a89d95cf87..6f7651a808 100644
--- a/tests/Imaging/StaticUrlBuilderTest.php
+++ b/tests/Imaging/StaticUrlBuilderTest.php
@@ -44,7 +44,7 @@ public function testPath()
         $this->generator->shouldReceive('generateByPath')->andReturn($path);
 
         $this->assertEquals(
-            '/img/'.$path,
+            '/img/'.ltrim($path, '/'),
             $this->builder->build('/foo.jpg', ['w' => '100'])
         );
     }
@@ -56,7 +56,7 @@ public function testFilenameHasNoAffect()
         $this->generator->shouldReceive('generateByPath')->andReturn($path);
 
         $this->assertEquals(
-            '/img/'.$path,
+            '/img/'.ltrim($path, '/'),
             $this->builder->build('/foo.jpg', ['w' => '100'], 'custom.jpg')
         );
     }
diff --git a/tests/TestCase.php b/tests/TestCase.php
index e8c5e54d68..2dedc5b788 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Assert;
 use Statamic\Facades\Config;
 use Statamic\Facades\Site;
+use Statamic\Facades\URL;
 use Statamic\Http\Middleware\CP\AuthenticateSession;
 
 abstract class TestCase extends \Orchestra\Testbench\TestCase
@@ -138,6 +139,8 @@ protected function setSites($sites)
         Site::setSites($sites);
 
         Config::set('statamic.system.multisite', Site::hasMultiple());
+
+        URL::clearUrlCache();
     }
 
     protected function setSiteValue($site, $key, $value)
@@ -145,6 +148,8 @@ protected function setSiteValue($site, $key, $value)
         Site::setSiteValue($site, $key, $value);
 
         Config::set('statamic.system.multisite', Site::hasMultiple());
+
+        URL::clearUrlCache();
     }
 
     protected function assertEveryItem($items, $callback)