🧠 Assets Cacher

• A lightweight Chrome extension to reduce bandwidth usage by caching frequently downloaded assets like images, scripts, and fonts, with per-site controls.

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🤔 What's the Big Idea?

Do you visit websites that are heavy on images or use the same JavaScript libraries on every page? Every time you navigate, your browser might be re-downloading these same assets, consuming your bandwidth and slowing down page loads.

Assets Cacher intercepts these requests. The first time an asset is downloaded, the extension saves a copy. On all subsequent requests for that exact same asset, it serves the saved copy directly from your local machine, resulting in near-instantaneous loads and saving you data.

✨ Key Features

• Aggressive Caching: Intelligently caches static assets like images, JS, CSS, and fonts to reduce redundant downloads.
• Bandwidth Savings Tracker: See a running total of the data you've saved in the popup and options page.
• Per-Site Control: Caching is enabled by default. You can easily disable it for any specific website with a single click.
• Advanced Cache Management (Options Page):
  • View global statistics (total items cached, total size, total bandwidth saved).
  • See a detailed table of every single cached asset, including its size and cache date.
  • Set a global cache eviction policy (e.g., automatically delete assets older than 30 days).
  • Purge the entire cache for all sites with one click.
• Smart Validation: Respects ETag and Last-Modified headers to automatically fetch fresh assets when they are updated on the server.
• Built for Manifest V3: Uses a modern, secure, and persistent architecture with IndexedDB for storage.

🚀 Installation

Since this extension is not on the Chrome Web Store, you can install it locally by following these steps:

1. Download the Code:

   • Clone this repository to your local machine:

     git clone https://github.com/Akhil-Chaturvedi/Assets-Cacher.git

   • Or, click the "Code" button on GitHub and select "Download ZIP", then unzip the file.

2. Open Chrome Extensions:

   • Open your Google Chrome browser.
   • Navigate to chrome://extensions in the address bar.

3. Enable Developer Mode:

   • In the top-right corner of the Extensions page, toggle on the "Developer mode" switch.

4. Load the Extension:

   • Click the "Load unpacked" button that appears.
   • In the file selection dialog, navigate to and select the Assets-Cacher folder (the one that contains manifest.json).
   • Click "Select Folder".

The extension is now installed! You should see the "Assets Cacher" icon (you may need to pin it) in your Chrome toolbar.

🛠️ How to Use

1. Navigate to any website. Caching is enabled by default and will start working in the background.
2. Check the Badge: The extension icon will show a green badge with the number of assets cached for the current site.
3. View Stats: Click the Assets Cacher icon to open the popup and see stats for the current site, including bandwidth saved.
4. Disable Caching: If a site isn't working correctly, simply use the toggle in the popup to disable caching for that domain.
5. Manage Everything: Click the "Options" link in the popup to access the global cache manager, see all cached files, and purge data.

⚙️ How It Works (The Technical Details)

This extension uses a persistent, service-worker-compatible architecture to cache assets.

1. Fetch and Convert (onCompleted): After a network request for a cacheable asset (like an image or script) finishes, the extension fetches it in the background. It then converts the asset's binary data into a data: URL (a Base64 encoded string).

2. Store in IndexedDB: This data: URL, along with metadata like the ETag, size, and the original website's domain (initiator), is stored in the browser's IndexedDB. This provides a large, persistent storage solution that works perfectly within a Manifest V3 service worker.

3. Intercept and Redirect (onBeforeRequest): Before any subsequent request is made, the extension checks its in-memory cache (loaded from IndexedDB). If a valid, fresh entry exists, it uses the chrome.declarativeNetRequest API to create a dynamic rule. This rule instantly redirects the browser's request to the stored data: URL, completely avoiding the network and serving the asset in microseconds.

This model is robust, fully persistent across browser sessions, and respects the technical constraints of the modern Manifest V3 platform.

📜 License

This project is licensed under the GPL-3.0 License.