The GIF is technically obsolete and still everywhere

CompuServe introduced the Graphics Interchange Format in 1987, when a fast modem moved about 1.5 kilobytes per second and 256 colors was a reasonable ceiling for consumer hardware. The animation extension arrived with the 1989 revision, almost as an afterthought. Nearly four decades later it remains one of the most recognisable file types on the internet.

Every replacement was technically better

• PNG arrived in 1996 with millions of colors and proper transparency, and APNG later added animation. It never displaced GIF for motion.
• Flash owned web animation for a decade and then vanished entirely.
• WebP compresses animation three to five times better and is supported everywhere. It is gaining ground slowly.
• Plain video in an MP4 is an order of magnitude more efficient and is what most platforms now serve behind the scenes.

Why it survived anyway

The GIF won on social properties rather than technical ones. It plays automatically, loops forever and has no sound, which turned out to be exactly the right behaviour for a reaction in a comment thread. It needs no player controls and cannot embarrass anyone by blasting audio in an open office.

It is also a single self contained image file. That makes it trivially shareable, embeddable and archivable, and it works in email, where video does not. Universality beat efficiency.

The quiet substitution

Here is the part most people miss. When you send a GIF from Giphy or Tenor today, you are usually not sending a GIF. The major platforms transcode to MP4 or WebM behind the scenes and serve that instead, because the bandwidth saving at their scale is enormous. The word stayed. The format underneath was swapped out.

So the GIF has become a description of a behaviour, a short silent auto-playing loop, rather than a file format. That is why it will outlive the file it is named after, and why converting a GIF to MP4 before sharing is almost always the right move.