It's disabled by default, but I had no idea this was added.
Firefox mobile users started noticing something peculiar this week when sharing links to WhatsApp. After hitting that share button, their messages were getting an unexpected tagline: βSent from Firefox π¦β with a direct link to the Mozilla app store listing.
The feature appeared quietly, with no fanfare or announcement from Mozilla.
https://piunikaweb.com/2025/11/26/sent-from-firefox-whatsapp-share-signature/
If I weren't using an extensively configured Librewolf already and this happened to me, I'd have dropkicked Firefox off my system faster than you could say "sent from Firefox"
Jumped ship after they started pushing AI. They were on Google's teat for some time... Apparently they moved on to some tech-bros dick.
Of all the things that have pushed me off a browser... This was about the least expected.