Since March 2019, we allow uploads of Animated GIF images up to 1MB of size.
It is also possible to add GIF images to your posts if you find them hosted somewhere else.
You can search for a GIF image in any Search Engine.
When you find the image you want, try to get the actual direct URL/Link of the image itself. This means that it's not enough to find the image inside another webpage. You must find the link for the image alone. Those links usually end with ".gif".
Example URL/Link for a GIF image:
Once you have a link similar to the above, copy that link and then, on Similar Worlds, press the following button:
In the window that opens, press "URL/Link", and then copy the link into the text box:
Press "Insert Image" and the code should appear in your new Post text.
When you submit your new Post, the image should appear for everyone.