MP4 to WebM Converter

Convert MP4 video files to WebM format directly in your browser using VP8/VP9 — no upload, no server, completely private.

Use the MP4 to WebM Converter

Convert MP4 to WebM

100% client-side — your video never leaves your device.

Need faster conversion? Use FFmpeg

For large files or batch conversion, FFmpeg is much faster than the browser.

# VP9 (best quality/size)
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 0 -crf 30 output.webm

# VP8 (fast)
ffmpeg -i input.mp4 -c:v libvpx -c:a libvorbis output.webm

Source Video

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Summary

This tool converts MP4 video files to WebM format entirely in your browser using the HTML5 MediaRecorder API with VP8 or VP9 codec support. No file is ever uploaded to a server — all processing happens locally on your device. WebM is an open, royalty-free format optimized for web delivery and is natively supported by Chrome, Firefox, and Edge.

How it works

  1. Select or drag an MP4 video file onto the drop zone.
  2. Choose your preferred output codec: VP8 (faster, wider support) or VP9 (better compression).
  3. Click "Convert to WebM" to start the client-side conversion using MediaRecorder.
  4. A progress indicator shows conversion status as frames are captured.
  5. When complete, click "Download WebM" to save the converted file to your computer.

Use cases

  • Prepare video files for web embedding without re-uploading to a server.
  • Convert MP4 recordings to WebM for use in HTML5 video tags.
  • Reduce video file size using VP9's efficient compression for web delivery.
  • Convert screen recordings or tutorials to a web-friendly format.
  • Create WebM files for use in web applications that require open formats.
  • Convert videos privately without exposing footage to third-party services.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu