FREE VIDEO TOOL
MP4 to WebM Converter
Convert MP4 videos to WebM (VP9 video, Opus audio) - smaller files that play natively in every modern browser.
Drop your MP4 video here
Multiple files supported
Why Use Our MP4 to WebM Converter?
VP9 Video, Opus Audio
Encodes with the same codecs YouTube and most modern browsers use natively for WebM, for smaller files at comparable quality.
Batch Convert Multiple Files
Drop in as many MP4s as you need and convert them one after another, downloading each finished WebM individually.
100% Private
Your videos are never uploaded anywhere. Conversion runs locally in your browser using a WebAssembly build of FFmpeg.
No Sign-up Required
Open the page and start converting immediately. No account, no install, no fees.
Frequently Asked Questions
Is my video uploaded to a server?
No. Conversion runs entirely in your browser. Your video is never uploaded anywhere.
Why convert to WebM?
WebM with VP9/Opus typically produces smaller files than MP4 at similar quality, and plays natively in every modern browser without a plugin.
Will this re-encode my video?
Yes. MP4 and WebM use different video codecs, so there's no fast shortcut - every file is re-encoded with VP9 and Opus.
Is this tool free?
Yes. It's free to use with no sign-up.
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