I didn’t find any current addons or solutions for doing so when I looked it up.
You can probably do it with Greasemonkey, have you tried that yet?
When viewing a gif (say https://i.imgur.com/l53kRnm.gifv) you can right click it and select “Show Controls”.
that isn’t strictly speaking a gif. imgur (among other image/video/etc hosting) can do a lot of tricks. that “.gifv” at the end of the url makes it present the “gif” as a video (mp4, in this case).
If you change the url to end with just “.gif”, then it’ll show it as an actual gif
I had tried this on Reddit and it worked … only to find out that it actually shows GIFs as videos, with URLs like this: https://preview.redd.it/ni50mhcst4eb1.gif?format=mp4&s=258d02a4fde68d53272c8d6a08f2ba648dfd2111. I tried it on this actual GIF but it’s not available https://www.google.com/search?client=firefox-b-1-d&q=web+gif+example#vhid=YGtfdlLW95ObWM&vssid=l.
That’s not a GIF, that’s gifv, a format from Imgur to show videos as GIFs. It doesn’t work when I try it on an actual GIF: https://www.google.com/search?client=firefox-b-1-d&q=web+gif+example#vhid=YGtfdlLW95ObWM&vssid=l.
I notice nobody has posted a helpful answer, it looks like there’s a few ways to handle this problem. The first way is a javascript bookmarklet that doesn’t like modern protections that stop javascript cross domains, but you can find it here: https://slbkbs.org/jsgif/ It seems to work on that page, and it needs the browser to be set to full screen to work.
There’s an addon on the extensions store, it needs a right click on every gif to open it in a new window and seems to work just fine: https://addons.mozilla.org/en-GB/firefox/addon/gif-scrubber3/
There’s also an addon that would need to be sideloaded, but I don’t know how good it would be. It seems to convert gifs into videos first, and needs a lot of work to get it going: https://github.com/brunoluiz/gifsane-extension
Finally there seems to be a website that will do the lifting for you, but it would need you to paste every gif into it manually: https://onlinegiftools.com/play-gif
