Convert Audio Video Interleave (.avi) to WebM Video (.webm) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .avi file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .webm file when it's ready.
AVI is a pre-internet container with no streaming support, while WebM is Google's open-source format specifically designed for web delivery. WebM uses VP8 or VP9 video (royalty-free alternatives to H.264/H.265) with Vorbis or Opus audio in a Matroska-based container. WebM is supported natively in every major web browser — Chrome, Firefox, Edge, Opera, and Safari (since macOS Big Sur) — making it the standard for HTML5 video when patent-free delivery is needed. Converting AVI to WebM produces a web-ready, royalty-free video file.
WebM is the standard for web video when you need browser-native playback without licensing concerns. YouTube uses VP9/WebM as its primary delivery format. If you are building a website, web application, or video hosting platform that serves HTML5 video, WebM is the most efficient royalty-free option. VP9 achieves compression comparable to H.265 — roughly 30–50% better than H.264 — meaning smaller files with the same visual quality.
FFmpeg decodes the AVI streams and re-encodes video to VP9 (or VP8 for faster encoding) using libvpx-vp9, and audio to Opus (or Vorbis) using libopus. VP9 encoding supports CRF mode (recommended: CRF 30–35 for web, 23–28 for high quality) with two-pass encoding for optimal bitrate distribution. The Matroska-derived WebM container supports cue points for seeking. VP9 encoding is significantly slower than H.264 but produces smaller files at the same quality.
VP9 at CRF 31 produces quality comparable to H.264 at CRF 23, but in a file roughly 30% smaller. Opus audio at 128 kbps is transparent for most content. The main tradeoff is encoding speed — VP9 is 3–10x slower to encode than H.264, making it better suited for encode-once-serve-many scenarios like web publishing.
| Device | AVI | WebM |
|---|---|---|
| Windows PC | Native | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
AVI to WebM conversion produces a web-optimized, royalty-free video file with excellent compression. WebM with VP9 and Opus is the gold standard for HTML5 video delivery across all modern browsers.
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Ochrana soukromí
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Funguje všude
| Native |
8MB free, 50MB Nitro
Jakýkoli prohlížeč, jakékoli zařízení
| Vlastnost | AVI | WebM |
|---|---|---|
| Celý název | Audio Video Interleave | WebM Video |
| Přípona | .avi | .webm |
| Nejlepší pro | Windows native | Web optimized |