WebM to MP4 Converter
Convert a browser-recorded WebM clip to universally-playable MP4, free and entirely in your browser.
What is WebM?
WebM is an open, royalty-free video format built for the web, using VP8/VP9 or AV1 video with Opus or Vorbis audio. Browsers, screen recorders (like OBS or built-in browser recording), and some download tools default to it because it’s lightweight and license-free.
Why convert WebM to MP4?
MP4 remains the safer bet for anything leaving the browser — video editors, mobile galleries, PowerPoint/Keynote, and older devices support MP4 far more consistently than WebM. Converting WebM to MP4 is the standard step before editing, presenting, or archiving a browser-recorded clip.
How to convert WebM to MP4
- Drop your WebM file. Drag and drop a WebM file, or click to browse. First use loads the ffmpeg.wasm engine (~31 MB, cached in your browser after).
- Confirm output is MP4. This page pre-selects MP4 as the output format — change it in the format picker if you’d rather export something else.
- Set quality and convert. Pick a quality or bitrate preset, then click Convert. Processing runs locally on your device and typically finishes in well under a minute for short files.
- Download. Click Download to save your MP4 file. Nothing was ever uploaded to a server.
Your file never leaves your browser — conversion runs locally via ffmpeg.wasm, not on a server.
Use Cases
- Import a WebM screen recording into a video editor that expects MP4
- Add a browser-downloaded WebM clip to a PowerPoint or Keynote slide
- Make a WebM video playable on an older phone, TV, or browser