It works regularly in Mozilla Firefox 129.0B9 X64. It is a pity that manual editing of a list of comparison of domains and UA is carried out only in JSON format, and not in something more accessible to non-specialists.

Upd. 0.6.6 (Oct 8, 2025) and Mozilla Firefox 148.0b12:

1. Selected "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36" from the list.
2. Clicked "Apply (all tabs)".
3. Clicked "Test UA".
4. webbrowsertools.com: "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:148.0) Gecko/20100101 Firefox/148.0".

The extension does not perform its main function.

I started to get blocked by websites as a bot while using this addon. Do not recommend.

This doesn't work at all, with any configuration, and hasn't seen an update in over a year. Version 0.6.1.1 is available on other extension stores, and I would package and install this myself, but there are no releases on GitHub.

Why it's so complicated to JUST SET USER AGENT TO SPECIFIC SITE?

прекрасная программа, очень помогает

Graphical glitches while add-on was installed and link addresses were showing up in the bottom corner without the /s? Not sure what kind of bug this is? Removed the add-on and everything is fine now. Why would an add-on that is used to spoof the User-Agent mess with graphical and character memory?

Thank you for this extension I can now watch Youtube videos without wattling forever for the video player to show up. I use windows 11 home supported on my hp pavilion laptop 32gb of ram intel core I7 8gen Firefox nightly 12864bit.