An indispensable asset in Firefox. It’s a huge lifesaver for testing responsive layouts across different platforms and helps bypass websites that artificially restrict access for Firefox users. A huge plus for the ability to configure custom strings and setup automatic rotation.

Red Flag: webpage claims "Optional permissions: Access your data for all web sites" but install dialog says this permission is *required*.

It's unclear why a UA switcher requires "Access your data for all websites" but that permission description says: "The extension could read the content of any web page you visit, as well as data you enter into those web pages, such as usernames and passwords. This is used for password managers, shopping tools, ad blockers, etc. " A UA switcher isn't any of those, so... why?

For a long time this was my go-to add-on for user agent removal and randomisation, but it stopped working at some point. I run it in custom mode, but it simply always sends my real User-Agent.

Hi, thanks for the add-on. It was a bit difficult at first to figure out how it works, but after I discovered that all the buttons have tooltips, it got much easier.

I have an enhancement suggestion: perhaps it would be more convenient if the filter in the popup window would not simply grey out items that don't match it, but hide (collapse) them, so that only what the user searches for is displayed.

I fully agree with the review by Cr: "This extension is unbelievably user-hostile. ..."

This extension is unbelievably user-hostile. I’m convinced the developer has some deep resentment toward anyone who isn’t a programmer. I genuinely can’t understand how something this frustrating to use ended up being officially recommended by Firefox. Now I finally understand why Firefox keeps losing market share. If I had the option, I wouldn’t even give it a single star.

Currently it works fine. Don't know why people reported different 4 months ago.
It does cause issues: Youtube subtitles can't be displayed, Claude uploads are getting rejected.

Pessima su Android!

It literally doesn't work most of the time. Sometimes it randomly does, but mostly it just doesn't do anthing

Doesn't work anymore.

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"