current version of 0.6.6 December 17, 2025 is broken on firefox 145.0.1. user-agent is not taking effect and noticed an error in debug-addon of firefox.
Reading manifest: Warning processing storage: An unexpected property was found in the WebExtension manifest.

was useful while it lasted

This worked until few days ago and then my YouTube videos will stop at 1.00 minute and then playback will crash

Stopped working. This is now absolutely useless, and no update seems to be forthcoming.

Does not function

This addon breaks youtube. After around 30 sec of playback the player stops and says "something went wrong"

This has so far not caused the dreaded Cloudfare veryifying loop that the agent switcher by ntninja does. I thought Cloudfare was just completely against agent switchers until I tried this one instead.

Very useful, thank you!

Works well compared to another UA switcher I've tried, the website whatismybrowser actually gets fooled by the custom UA string, when with the other, it says Firefox on Linux (what I am indeed using) but announcing that it's (ua string). Only one problem. On Firefox forks that use older Firefox versions, this add-on is completely unavailable. Wtf? This is why I have experience with other UA changer add-ons.

Works with websites that do not require up to date user agent information. Chrome User agent is stuck on 135 while current version is 139. For instance : does not work with Google.com

I'm so disappointed that you can no longer assign specific user-agents to specific containers. I miss this feature please add it back.
That being said, this is still a great extension to have, probably the best of it's kind.

worked great for a while, but unfortunately the white list mode broke on the latest version.

It seems that rolling back to the previous version could make it work again.

Does not work anymore..

This addon was great untill Per-container UAs stopped working! Pls Fix!!!

This is a badly behaving extension that is breaking youtube video playback and google search, causing google to constantly spam captchas everytime I try to use the search engine. I do not recommend installing this!