Convert MP4 videos to WebM format. Perfect for web embedding and HTML5 video. Free online converter.
Conversion settings — add a file to adjust
Upload your .mp4 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.
WebM is the web's native video format, designed by Google specifically for HTML5 video delivery. While MP4 works well on most platforms, WebM offers royalty-free encoding and often achieves smaller file sizes at equivalent quality—valuable for website optimization and cross-browser video.
Our MP4 to WebM converter transforms your videos using VP9 encoding for maximum compression efficiency. The result is web-optimized video files that load faster and consume less bandwidth while maintaining excellent visual quality.
Web performance benefits from WebM. The format typically produces 20-30% smaller files than MP4 at equivalent quality. For websites serving video content, this means faster loading, reduced bandwidth costs, and better user experience on mobile networks.
Browser optimization favors native formats. While modern browsers play both MP4 and WebM, some browsers handle WebM more efficiently. Providing WebM alongside MP4 ensures optimal playback across all browsers.
Open source and licensing considerations matter for some projects. WebM is completely royalty-free; H.264 (in MP4) involves patent licensing. For projects with licensing concerns, WebM avoids potential complications.
Our converter uses VP9 encoding with Opus audio—the standard WebM configuration for maximum efficiency and quality. Two-pass encoding optimizes bitrate distribution for best quality within target file size.
Quality settings translate from CRF-style presets: High (CRF 20), Medium (CRF 30), Low (CRF 40). Resolution and frame rate preserve from source by default, with options to downsample for additional size savings.
VP9 encoding achieves excellent quality at lower bitrates than H.264. Your WebM files may look better than the MP4 source at the same file size, or equal quality at smaller size. The conversion is advantageous for web delivery.
| Device | MP4 | WebM |
|---|---|---|
| Windows | Native | Native |
| macOS | Native | Partial |
| iOS | Native | Partial |
| Android | Native | Native |
| Linux | Native | Native |
| ChromeOS | Native |
| Speed | Slower than other video conversions — VP9 encoding is compute-intensive (measured ~40 s for a 10-second clip). |
| Output size | Comparable to the source; VP9 trades encode time for efficiency. |
| Quality | Re-encoded to VP9/Opus, the web's open format — ideal for HTML5 and bandwidth-sensitive delivery. |
| Engine | FFmpeg (libvpx-vp9), server-side. |
Measured on our servers, June 2026, on a 10-second 1280×720 clip.
Resolution: 1920x1080
Bitrate: 8-12 Mbps
YouTube accepts WebM natively with VP9 codec
Resolution: 1080x1920
Bitrate: 3.5 Mbps
WebM not recommended — use MP4 for Instagram
Resolution: 1080x1920
Bitrate: 6 Mbps
WebM may not be accepted — use MP4 instead
Resolution: 1280x720
Bitrate: 3 Mbps
WhatsApp does not support WebM — convert to MP4
Resolution: 1280x720
Bitrate: 5 Mbps
Twitter accepts WebM uploads natively
Resolution: 1280x720
Optimize your video for the web with our MP4 to WebM converter. Create smaller, faster-loading video files perfect for HTML5 embedding and modern web delivery.
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Borja konvertera direkt
Fungerar overallt
| Native |
Bitrate: 5 Mbps
WebM embeds and plays natively in Discord
Valfri webblasare, valfri enhet
| Funktion | MP4 | WebM |
|---|---|---|
| Fullstandigt namn | MPEG-4 Part 14 | WebM Video |
| Filandelse | .mp4 | .webm |
| Bast for | Universal compatibility | Web optimized |