Configure Browsers

Clear Cache

To ensure all requests are sent and captured, clear your browser's cache before beginning a capture.

IE, Chrome, Safari, and Opera


  • To capture HTTP traffic from Firefox 4+, either:

    • Click Tools > Monitor with Fiddler > Use Fiddler automatically to configure with FiddlerHook, or

    • Click Tools > Options > Advanced > Network > Settings > Use System Proxy Settings.

    Use System Proxy Settings

  • Capture HTTPS traffic from Firefox

Manual Configuration

To manually configure any browser to send traffic to Fiddler, set the browser to connect to a proxy server. This setting is usually in the Options or Preferences menu. Use these settings:

Address: Port: 8888

Note: If a browser uses these settings, revert these settings after you close Fiddler, or the browser will not load pages. For example, Firefox will show the following error message:

Firefox Proxy Error

To instead allow Fiddler Classic to automatically enable and disable the proxy, use Proxy Auto-configuration with a URL pointing to %userprofile%\Documents\Fiddler2\Scripts\BrowserPAC.js.

For example, in Firefox, click Tools > Options > Advanced > Network > Settings, and input the URL of the BrowserPAC.js.

Automatic proxy configuration URL

To find the correct auto-configuration URL from Fiddler:

  1. Click Tools > Options > Connections.
  2. Clicking the Copy Browser Proxy Configuration URL link.

Copy Auto-Correct URL

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