Sailfish-browser esr91 user-agent fix needed for broken facebook.com website

General
1

As reported in (jolla browser) Sites that aren’t working in ESR 91 - #105 by d.d thread it seems facebook.com website stopped working with the stock sailfish-browser on 25th of August 2025. Confirmed with sailfishos 5.0.0.68, esr91, sony xperia 10 iii.

the error given by facebook website is “Facebook is not available on this device. To continue using it, switch to another mobile device or desktop.”

This most probably means a new browser user-agent override needs to be added to make facebook.com website happy. Has anyone found a new working user-agent yet?

The default user-agent used for facebook.com by sailfish-browser esr91 is:

“Mozilla/5.0 (Linux; Mobile; rv:91.0) Gecko/91.0 Firefox/91.0”

(source: https://browser.sailfishos.org/gecko/91.0/ua-update.json )

Custom user-agent for sailfish-browser can be manually set by:

  1. setting environment variable CUSTOM_UA before starting sailfish-browser.

  2. or editing $HOME/.local/share/org.sailfishos/browser/.mozilla/prefs.js and setting user_pref(“general.useragent.override”, "new-ua-string“);

I tried quickly with the most obvious change of changing the version number from 91.0 to 102.0 and to 140.0, but those didn’t do the trick unfortunately.

1 Like
2

So… if this didn’t work, what makes you think a simple override will fix it?

3

well, maybe some other keywords need to be tweaked aswell. this needs some investigation and testing.

4

…or it is *actually* incompatible. Hard to know without nay information.

5

could be. we’ll find out..

6

Facebook works in Angelfish browser from Chum, except messages with end2end encryption which needs newer browser.