Setting a useragent only for specific sites

aargl's Avatar


24 Oct, 2020 09:45 AM

I'm just sharing my recent find to anyone interested. :-)
In order to comply with Cameron's advice to stick to Default FF45 useragent as much as possible, while still being able to change it only for certain sites, you can create a general.useragent.override.[name_of_the website] key in about:config with the correct user agent as a value.
This way you keep FF45 most of the time and switch to something else only for the itchy sites.
I had tried it a few months ago with youtube and it didn't work, so I gave up, but I must say that I tried through user.js or prefs.js, not directly in about:config, who knows if it was that or youtube detecting fingerprint or else, but I've just found it's working for other sites!
It might not work for your specific site, but at least it's something to try.

Here's how it looks for my bank website — can't connect with anything below FF60.
In about:config, right click and create the key
Give it value Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Firefox/60.0
Of course, give the value that works for your specific site. ;-)
You can try various ones using (only version 0.3.0 installs, though you can't access its options as in Firefox).

  1. 1 Posted by aargl on 10 Nov, 2020 10:14 AM

    aargl's Avatar

    A little update: this works if you keep TFF prefs useragent to FF45. If you change it for something else, the global setting precedes the override key!
    This might explain why it didn't work when I first tried this trick on Youtube, as my global useragent was set to FF52 by that time. :-)

  2. Support Staff 2 Posted by Cameron Kaiser on 10 Nov, 2020 04:05 PM

    Cameron Kaiser's Avatar

    Yes, that's intentional, since the global setting is the only one exposed in the UI. This way it's obvious why something is occurring. If/when other options are exposed in the UI, then I'll reconsider this.

  3. 3 Posted by aargl on 10 Nov, 2020 05:37 PM

    aargl's Avatar

    Of course. :-)

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