Capturing Traffic

Out of the box, Fiddler Everywhere provides an automatic capturing functionality though the system capturing options and the preconfigured browser capturing feature.

The following table demonstrates the major differences between the two functionalities.

Feature System Capturing Preconfigured Browser Capturing
Additional configuration Requires trusting of the root certificate for enabling HTTPS capturing. No additional configuration is needed.
Modification of the system proxy Requires modification of the system proxy. Automatically configures the system proxy for Google Chrome.
Explicit addition of the trust certificate Requires you to add the certificate in the OS keychain. Automatically configures the trust certificate for Google Chrome.
Capturing of browser traffic Supports all browsers. Support for all Chromium browsers.
Capturing of other applications traffic Yes. Supports traffic capturing on virtually any application that uses the system proxy. No.
Required administrative access Requires OS admin rights for installing and trusting a root certificate and for modifying the system proxy. Requires user rights for starting a Chromium browser with custom parameters.
Working with VPN tooling Requires Cisco VPN support. Provides multiple VPN tooling support out-of-the-box.
Captured output Captures all traffic that goes through the system proxy. Captures only the traffic from the preconfigured browser instance.

System Capturing

Once Fiddler Everywhere is installed, and its root certificate trusted, you can utilize the web-traffic capturing of the proxy client.

The client logs all HTTP and HTTPS traffic between your computer and the Internet and helps you analyze and debug the incoming and outgoing traffic from virtually any application that supports a proxy—Google Chrome, Firefox, Microsoft Teams, Outlook, and more. You can use the captured traffic to debug issues, identify performance bottlenecks, or share it with your teammates.

To capture system traffic with Fiddler Everywhere:

  1. Start Fiddler Everywhere. Make sure that it is correctly configured as described in the First Steps tutorials.

  2. Switch Live Traffic to Capturing. Your incoming and outgoing traffic will be immediately captured and displayed in the Live Traffic.

    Enabling Live Traffic

When you switch Live Traffic to Capturing, open a browser and type an arbitrary web address. As a result, Fiddler Everywhere will immediately intercept the request, and Live Traffic will be populated. The Result field for that arbitrary web address will return 200, which means that your first request is successfully captured with Fiddler Everywhere.

Preconfigured Browser Capturing

The preconfigured browser capturing is a feature that allows you to capture traffic from a specific browser instance. Currently, Fiddler Everywhere supports preconfigured browser capturing only for Chromium browsers.

The feature is useful when you need to capture browser traffic but your environment doesn't allow you to change the system proxy or to install and trust root certificates. It also solves the compatibility issues with some VPN and third-party security tools, which modify the system proxy. Additionally, it allows you to focus your capturing on a sandboxed browser instance and prevent capturing other system traffic.

To start the preconfigured browser capturing with Fiddler Everywhere:

  1. Install Google Chrome or other Chromium browser.

  2. Start Fiddler Everywhere. No additional configuration is needed. To prevent polluting the Live Traffic list, you can disable the Live Traffic toggle.

  3. Click Open Browser from the Live Traffic toolbar.

    the "Open Browser" option for opening preconfigured browser for automatic capture

  4. Enter the URL in the newly opened Chrome window. Fiddler Everywhere immediately starts capturing all the traffic generated from the preconfigured browser.

To change the preconfigured browser, from the Browsers sub-menu either assign a path to third-party Chromium browsers, like Edge, Brave, and Vivaldi, or change the default path to the Google Chrome browser.

Additional Resources

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