So, a bit of pedantry that often doesn’t matter but may be useful to be aware of:

We don’t actually want anyone using “GIFs” anymore. It’s a very inferior format that doesn’t load well on phones. It’s a handy term that can refer to silent looping clips - but most of the time even when they’re in use, they’re done as muted video links. Some sites call these GIFVs or whatever else.

So if you have an mp4 video that you think would be funny muted and looping, don’t try to convert it to GIF, just see where you can upload and embed it. Granted, it sounds like Lemmy still has issues on the embedding bit.

I think you might have better luck uploading them in webp format.

example

After a little of investigating it seems that Lemmy currently unintentionally blocks video files from loading from different sites.
That means that only GIFs (internally handled as mp4 I think) from the same site will load correctly right now.

A fix for this has apparently been implemented 4 days ago, so it just depends on when the fix is officially released (currently in beta for version 0.18) and when your instance updates.

Until then, you'll just have to open the comments or posts on their original site.

Same, kinda missing all the videos and gifs from that other place