About remote debugging of Chrome

[hanamichi77777]

In the latest version of Chrome, access from Selenium is no longer possible. It will work if you set it as follows when starting.

wshell.Run "chrome.exe --remote-debugging-port=9222 --user-data-dir=C:\ChromeDebugProfile

(Additional)2025/6/2
The location and name of the folder are not fixed.
If you do not create it in advance, it will be created automatically.

[GCuser99]

@hanamichi77777 thanks for starting this discussion. Can you elaborate on this issue?

What version of Chrome browser are you using?

When you say "In the latest version of Chrome, access from Selenium is no longer possible.", are you talking about connecting to a previously open browser instance via caps.SetDebuggerAddress "localhost:9222", or are you referring more broadly to accessing Chrome using driver.OpenBrowser?

I can perform the latter ok on my system (Chrome v136.0.7103.93).

I did notice that running test_remoteDebugger in the test_capabilities module timed-out using chrome. When I used the arguments in your OP it worked (see code below).

Do you know if this change is a Chrome/WebDriver bug? If so, do you have any references?

Using MS Edge works as usual and does not seem to be affected (yet).

Sub test_remoteDebugger()
    'This test demonstrates how to connect to an existing Edge\Chrome browser instance and automate tasks.
    'An example usage case - you need to manually login to a website first and then run some automation tasks.
    'Below creates a shortcut on the user's Desktop to the browser's executable on port 9222 using the default profile.
    'Then we open the browser before starting the WebDriver - in a typical use case all of above would be performed manually.
    'Then we start WebDriver, setting the debugger address to port 9222 and perform automated tasks using SeleniumVBA.
    
    'To manually create a shortcut on Desktop type this into a new shortcut location:
    '"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --remote-debugging-port=9222 --user-data-dir="<path to temp user profile directory>"
    '"C:\Program Files\Google\Chrome\Application\chrome.exe" --remote-debugging-port=9222 --user-data-dir="<path to temp user profile directory>"
    
    Dim driver As SeleniumVBA.WebDriver
    Dim keys As SeleniumVBA.WebKeyboard
    Dim caps As SeleniumVBA.WebCapabilities
    Dim wshell As Object
    Dim browser As String
    Dim keySeq As String
    Dim debugProfile As String
    
    Set keys = SeleniumVBA.New_WebKeyboard
    Set driver = SeleniumVBA.New_WebDriver
    
    Set wshell = CreateObject("WScript.Shell")
    
    browser = "chrome" '"chrome" or "msedge"
    
    '--------------------------------------------------------------------------------------------
    'In typical use case this section would be performed manually
    'If you manually created the Desktop shortcut shown earlier, and opened your browser via the shortcut
    'then this code block is redundant. It is here for testing only.
    Select Case browser
    Case "chrome"
        'first must kill existing chrome processes
        wshell.Run "taskkill /f /t /im chrome.exe", 0, True
        'create a shortcut on the Desktop
        With wshell.CreateShortcut(wshell.SpecialFolders("Desktop") & "\Chrome_test.lnk")
            .targetPath = Environ("ProgramFiles") & "\Google\Chrome\Application\chrome.exe"
            .WorkingDirectory = Environ("ProgramFiles") & "\Google\Chrome\Application"
            '.Arguments = "--remote-debugging-port=9222 --profile-directory=""Default"""
    '--------------------------------------------------------------------------------------------
            'with above line this fails in Chrome 136 - replaced above with
            '@hanamichi77777's code line and it works!
            'see https://developer.chrome.com/blog/remote-debugging-port for more info...
    '--------------------------------------------------------------------------------------------
            debugProfile = Environ("USERPROFILE") & "\Documents\ChromeDebugProfile"
            .Arguments = "--remote-debugging-port=9222 --user-data-dir=""" & debugProfile & """"
            .Save
        End With
        'open the shortcut made above
        wshell.Run wshell.SpecialFolders("Desktop") & "\" & "Chrome_test.lnk"
    Case "msedge"
        'first must kill existing edge processes
        wshell.Run "taskkill /f /t /im msedge.exe", 0, True
        'create a shortcut on the Desktop
        With wshell.CreateShortcut(wshell.SpecialFolders("Desktop") & "\Edge_test.lnk")
            .targetPath = Environ("programfiles(x86)") & "\Microsoft\Edge\Application\msedge.exe"
            .WorkingDirectory = Environ("programfiles(x86)") & "\Microsoft\Edge\Application"
            .Arguments = "--remote-debugging-port=9222 --profile-directory=""Default"""
            .Save
        End With
        'open the shortcut made above
        wshell.Run wshell.SpecialFolders("Desktop") & "\" & "Edge_test.lnk"
    End Select
    '--------------------------------------------------------------------------------------------
    
    'now we start automating the existing browser instance
    Select Case browser
    Case "chrome": driver.StartChrome
    Case "msedge": driver.StartEdge
    End Select
    
    Set caps = driver.CreateCapabilities(initializeFromSettingsFile:=False)
    
    'set debugger address to same port as browser
    caps.SetDebuggerAddress "localhost:9222"
    
    driver.OpenBrowser caps
    
    driver.NavigateTo "https://www.wikipedia.org/"
    driver.Wait 1000
    
    keySeq = "Leonardo da VinJci" & keys.LeftKey & keys.LeftKey & keys.LeftKey & keys.DeleteKey & keys.ReturnKey
    
    driver.FindElement(By.ID, "searchInput").SendKeys keySeq

    driver.Wait 1500
    
    'this will close the pre-existing browser window (thanks to @hanamichi7777)
    'driver.ExecuteCDP "Browser.close"
    
    driver.CloseBrowser
    
    driver.Shutdown
End Sub

[hanamichi77777]

hello,@GCuser99
The version of Chrome I'm using is 136.0.7103.93.
It doesn't work when accessed via "localhost:9222".
But the regular OpenBrowser works.

This is not a bug but for security reasons, as explained in the following URL:
https://developer.chrome.com/blog/remote-debugging-port

[Pat075]

Great! Thanks, I had the same question ;)

[GCuser99]

Ok, awesome - thanks for the clarification and the link!

[hanamichi77777]

Hello,@GCuser99
This seems to work without the taskkill below:

wshell.Run "taskkill /f /t /im chrome.exe", 0, True

[GCuser99]

Hello,@GCuser99 This seems to work without the taskkill below:

wshell.Run "taskkill /f /t /im chrome.exe", 0, True

Yeah, I can run it without that line as long as I don't have any prior instances of chrome/edge open.

[hanamichi77777]

Thank you for @GCuser99

driver.CloseBrowser doesn't work in 9222.
But it works if you use the following CDP

driver.ExecuteCDP "Browser.close"

[hanamichi77777]

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