AVI to WebM Converter
Convert AVI to WebM free — no upload, no signup
To convert AVI to WebM, drop your AVI video into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. Turn old AVI clips into web-ready WebM.
Drop videos here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
If the video already uses codecs that fit the new format, Fylo repackages it instantly with no quality loss.
Advanced
How to convert AVI to WebM
Add your AVI videos
Drag and drop AVI files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Choose quality (optional)
Balanced quality suits most videos. If the codecs already fit WebM, Fylo repackages the file instead of re-encoding it, with no quality loss.
Convert and download
Click Convert, then download each WebM file or all of them as one ZIP.
Why convert AVI to WebM?
AVI doesn't play in browsers. Converting to WebM lets you embed legacy footage on a web page with the HTML5 video tag.
What happens when you convert AVI to WebM?
The AVI is re-encoded to VP8 video and Vorbis audio. File size is usually similar to or smaller than the AVI. For maximum compatibility on phones, MP4 is often the better web choice.
How does Fylo convert AVI to WebM?
Fylo reads the AVI with ffmpeg compiled to WebAssembly and writes VP8 with Vorbis audio, using libvpx's real-time preset so encoding stays practical in a browser. AVI's usual codecs (MPEG-4 Part 2 (Xvid/DivX), MJPEG) can't go into WebM as-is, so the video is re-encoded. Speed depends on your device: short phone clips take seconds, while on our slow test PC a 2-minute 1080p video took about 10 minutes. Only the first video and audio track are kept, and the original resolution is preserved unless you pick 1080p, 720p or 480p under Advanced.
What's the difference between AVI and WebM?
AVI (Audio Video Interleave) was introduced by Microsoft with Video for Windows in 1992. It's based on the RIFF container used by WAV and stores interleaved chunks of audio and video. In the 2000s, AVI files with DivX or Xvid (MPEG-4 Part 2) video and MP3 audio were the standard for downloaded movies.
WebM was announced by Google in 2010 as an open, royalty-free alternative to H.264 for HTML5 video. It's a subset of Matroska restricted to VP8, VP9 or AV1 video and Vorbis or Opus audio. Browser screen recorders and many web tools save WebM by default.
Learn more: AVI format guide · WebM format guide
| Property | AVI | WebM |
|---|---|---|
| Developed by | Microsoft | |
| Introduced | 1992 | 2010 |
| Typical video codecs | MPEG-4 Part 2 (Xvid/DivX), MJPEG | VP8, VP9, AV1 |
| Typical audio codecs | MP3, PCM, AC-3 | Vorbis, Opus |
| Plays in web browsers | No | Yes — Chrome, Edge, Firefox, Safari 14.1+ |
| Compatibility | Windows, VLC, older DVD players and TVs | Browsers, Android; limited in editors and on iPhone apps |
| Best for | Legacy players, old Windows software | Royalty-free web video, screen recordings |
Frequently asked questions
WebM or MP4 for my website?
MP4 (H.264) plays everywhere; WebM is royalty-free and works in all modern browsers. Many sites offer both.
How long will it take?
Roughly real time for SD footage on a laptop; HD takes longer.
Is my AVI file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your AVI file is read directly from your device and never sent anywhere.
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