Will the MP4 loop automatically?

The MP4 itself does not loop — the player has to. In HTML, add autoplay loop muted playsinline on the <video> element.

What if the GIF has a non-even width?

H.264 requires even dimensions; this tool pads odd widths/heights by one pixel so encoding never fails on rare sizes.

ffmpeg.wasm is ~25 MB and is downloaded once, then cached for instant subsequent runs.

将动态 GIF 转为 MP4 视频 — 动态效果相同，文件体积大幅缩小。

100% client-side · ffmpeg.wasm · no upload

Animated GIF

Quality (CRF) Use yuv420p (broad compatibility)

Pick a GIF file to begin.

Faster page loads — replace a 6 MB GIF hero with a 300 KB looping MP4.
Posting to Twitter / X, which converts uploaded GIFs to MP4 server-side anyway.
Mobile-friendly product loops that don't burn data plans.

Will the MP4 loop automatically?: The MP4 itself does not loop — the player has to. In HTML, add <code>autoplay loop muted playsinline</code> on the <code><video></code> element.
What if the GIF has a non-even width?: H.264 requires even dimensions; this tool pads odd widths/heights by one pixel so encoding never fails on rare sizes.
Why is the first run slow?: ffmpeg.wasm is ~25 MB and is downloaded once, then cached for instant subsequent runs.

Last updated: 2026-05-20 By jarvisbox