Pending Review
Last Updated: 08 Jul 2019 19:05 by James
Created on: 03 Jul 2019 00:23
Type: Bug Report
Need configuration option to enable proxy support for websocket protocol


Fiddler does not set up it's proxy server for the websocket protocol.  Applications looking at the global proxy settings are told by WebRequest.DefaultWebProxy.IsBypassed(Uri) that no proxy server should be used for the specified wss Uri.


Replication steps:

1. Have a .NET application that uses websockets and checks WebRequest.DefaultWebProxy.IsBypassed(Uri) to see if a proxy should be used for a wss Uri.

2. Try to use Fiddler to observe websocket traffic



After turning on fiddler, enable "Use the same proxy server for all protocols" in the Internet Options / Advanced Proxy settings screen.

Posted on: 08 Jul 2019 19:05

Some of my colleagues are seeing this error message when clicking that checkbox.

Can Fiddler at least stop caring if the "Use the same proxy server for all protocols" checkbox is checked?

Attached Files:
Posted on: 03 Jul 2019 14:00

This is effectively a bug in the client framework (e.g. .NET).

The checkbox in question is NOT designed to have any impact on WebSocket proxy selection.

[Authoritative Source: I own this checkbox.]