Capture HTTP and HTTPS sessions for debugging using Fiddler

Fiddler is a free web debugging proxy that logs all HTTP/HTTPS traffic between your web application and the Internet. You can download Fiddler from the Telerik official site.

Capturing session data with Fiddler can be useful for troubleshooting scenarios such as:

  • When no user actions are captured for your application, the RUM JavaScript isn't injected, and the beacon signal isn't sent back.
  • When a JavaScript error caused by the RUM JavaScript affects your application.
  • In case of missing user actions, for example, a special interaction with the application.

You can upload exported Fiddler sessions to your organization's incident management system to facilitate issue resolution.

Create an HTTP session

You can use Fiddler to create an HTTP session of the monitored web application.

  1. In Fiddler, go to Tools > Fiddler Options > HTTPS.
  2. Select Capture HTTPS CONNECTs and Decrypt HTTPS traffic.
    Setting HTTPS options in Fiddler
  3. Go to File > Capture Traffic or press F12 to turn off capturing. Clear your browser's cache so that all cached items are removed and downloaded again.
  4. Go to File > Capture Traffic or press F12 to start capturing traffic again.
  5. Reproduce the problem scenario to demonstrate that the issue occurred within your application. Make sure the affected page is fully reloaded after restarting traffic capture.
  6. When done, go to File > Save > All Sessions.

Common mistakes when using Fiddler

Alternatives to Fiddler sessions