Graphics Interchange Format — indexed-color raster images and simple animation.
| 0x00000000 | 474946383961 | GIF89a | 'GIF89a' (or 'GIF87a') |
GIF is limited to a 256-color palette per frame but supports looping animation and one bit of transparency, which is why it survived into the meme era. The header is the ASCII string GIF87a or GIF89a naming the spec version.
Have a file that might be GIF? Identify it with the File Type Identifier — it reads the magic number locally, nothing is uploaded. Or browse all formats.