Last Updated: 10 Jul 2019 10:38 by ADMIN
Created on: 23 Nov 2016 05:59
Type: Feature Request
Support Sec-WebSocket-Extensions: permessage-deflate
WebSockets offer a mechanism for doing compression of messages. Fiddler's WebSocket Inspector should provide a simpler means of viewing such content.

The mechanism looks to be a simple DEFLATE operation: https://tools.ietf.org/html/rfc7692
Posted on: 23 Nov 2016 06:00
Workarounds Today:

Sec-WebSocket-Extensions: permessage-deflate;client_max_window_bits=15
If you need to manipulate this stream, you could write a FiddlerScript rule that removes this header from the WebSocket handshake and this should force the communication to fall back to uncompressed traffic.
Alternatively, on a one-off basis, you can use the Inspect As Response button to add a message to the WebSessions list:
Use F2 to enable editing of the response and add a Content-Encoding: deflate header:
Hit F2 to save the change, and you can now use the Transformer or yellow bar to decompress the text:
Posted on: 23 Nov 2016 06:00
Note, supporting permessage-deflate without the


parameters (meaning that context takeover is allowed) likely would be pretty tricky because I don't think the DEFLATE code inside Fiddler is able to reuse a single compression context across multiple operations.