You'd think there's be an option to fake your Firefox version, too. I remember there being an extension that let me do this and thought this was it. Too bad.

Android Firefox not work...

Android版Firefoxでうまく動きません…

Muy Buena

This user agent switcher works well with Firefox Quantum, it modifies the user agent via the HTTP request header and also the JavaScript property navigator.userAgent.
I noticed it does not take effect on https://addons.mozilla.org, I don't know if it is a feature or a bug.

Recommendation: instead of displaying deprecated mobile operating systems like Symbian and Firefox OS, the addon should add Sailfish OS to the list (maybe BlackBerry also).

It would be good to add the possibility to enter multiple custom user agent instead of just one, like this addon (not supported with latest Firefox): https://addons.mozilla.org/en-US/firefox/addon/user-agent-switcher/

很好。很方便。

Wq

I installed this on FF 57 running on Fedora 25. No matter how I configured it, it showed that I was running FF 52 under Windows, even after I restarted FF. I uninstalled it, restarted FF and no change. I had to go into about:config to undo the damage. Utterly worthless.

It works and support Firefox Quantum 57.0.

I used Random Agent Spoofer which does not work in FF57. This extension is about as good. Does not randomize automatically, but easily changed with a few clicks. Just as with R. A. S., Youtube knows Google's Chrome browser and will not allow you in the site. Just spoof another browser temporarily and go on.

Worked well for a long time. Now I am getting constant reCaptcha hCaptcha and all sorts of Cloudflare flags...
It is a shame that you cannot change the user-agent on url-based or tab based.

very good extension, works for my use case

Switched from Random Agent Spoofer after the update to Firefox 57. Missing a lots of functions ...
Also why can't I use a weird OS/Browser combo like FreeBSD/Edge? And a timer is missing, and a random button ...

I've installed and tested it on Firefox (Android) 57.0. No matter what I select from the web-extension popup, my useragent remains unchanged at useragent-detection websites.

很好用的组件

I was looking for a Firefox 57-compatible replacement for UA-Control, which let me map different domains to different user-agents. This at least lets me do that with one alternate user-agent, so it's a lot better than nothing, however I wish it was more powerful.

Doesn't work for stable Firefox on Android..Note5.