WebM to GIF Converter

WebM is the video format of browsers, screen recorders, Discord and Telegram stickers and many download sites. A GIF still plays in places a video cannot: e-mail signatures, older forums, README files and chat apps that only animate GIFs. This converter turns part of a WebM into a looping GIF with a palette built from the clip itself. WebM stickers and overlays with a transparent background stay transparent. It runs in your browser with the ffmpeg engine (about 30 MB, downloaded once); the video is never uploaded.

How to use this tool

1. Choose a WebM file (VP8 or VP9; other video formats work too).
2. Enter the start time and the number of seconds to use; pick the frame rate, width and speed.
3. For a transparent sticker, keep "Keep the transparency", or fill it with a colour.
4. Choose colours, dithering and looping, then download the GIF.

Formula

Frames = seconds used ÷ speed × frame rate

The engine first builds the best 256-colour palette for the clip (palettegen, counting mostly the parts that change), then maps every frame to it (paletteuse) and stores only the changed rectangle of each frame. Transparent VP8/VP9 video is read with the libvpx decoder, which understands the separate alpha layer; pixels more than half transparent become transparent in the GIF.

Example

A 3-second WebM sticker at 15 fps gives 3 × 15 = 45 frames. At 320 px wide that is typically 300–900 KB; the same 3 seconds of a 1080p screen recording at 480 px and 10 fps (30 frames) usually lands at 1–3 MB.