How to use it
- Add your files. Drop AVI files on the page or use Choose files. Folders and ZIPs work too.
- Check that WebM is selected. WebM is already chosen on this page.
- Adjust options if you need to. Quality, size and other settings appear when the format has them.
- Convert and download. Press Convert; with several files, “Download all” gives you one ZIP.
What happens to your file
The AVI file is opened in your browser and its video and sound are re-encoded into WebM. Common formats use the browser’s built-in encoders (fast, hardware-accelerated); others use FFmpeg compiled to WebAssembly, which downloads once (about 32 MB) and then works offline.
Resolution and frame rate are kept. Re-encoding a lossy video loses a little detail, so choose the highest quality setting if you will edit the result.
About AVI and WebM
AVI: AVI is Microsoft’s older video container, still used by cameras, DivX/Xvid files and older software.
WebM: WebM is the open web video format (VP8/VP9 with Vorbis or Opus sound), made for browsers.
Questions
Is my AVI file uploaded?
No. The conversion runs inside this browser tab, and the WebM is created on your device. Nothing is sent to a server.
Is there a file size limit?
No fixed limit: files are processed by your device, so very large videos depend on its memory. Computers handle several GB; phones are best with smaller files.
Can I convert several AVI files at once?
Yes. Drop as many as you like, a folder or a ZIP; “Download all” saves every WebM in one ZIP.