How GIF looping works
Looping isn’t part of the original GIF specification. It was added by Netscape Navigator 2.0 as an application extension block containing a repeat count: 0 means loop forever, and a missing block means the GIF plays once. That’s why some GIFs stop after one play — the block is simply absent. This tool writes the block for you.
Viewers interpret finite counts slightly differently: most treat the number as extra repeats after the first play. If an exact number of plays matters, “Repeat inside the file” bakes the repetitions into the frames themselves, which behaves identically everywhere. You can see a GIF’s current loop setting with the GIF Tester.
Seamless loops
A loop that restarts abruptly looks like a glitch. Try trimming to a natural cycle, making a boomerang, or adding a short end pause here so the restart feels intentional. GIFs damaged by other tools — wrong speed, missing loop, cut-off ending — can be repaired in one go with Fix GIF.