MP4 to WebM converter
Convert MP4 (the universal H.264 video format) into WebM, which smaller files tuned for fast web playback. Everything happens locally in your browser — no uploads, no servers, and no waiting in a queue.
MP4 to WebM — common questions
Is the MP4 to WebM converter free?
Yes — it's completely free, with no sign-up, no watermark, and no limit on how many files you convert.
Are my MP4 files uploaded to a server?
No. The conversion runs entirely in your browser, so your MP4 file never leaves your device and is never uploaded.
How do I convert MP4 to WebM?
Drop your MP4 file into the tool above, then click the convert button. The WebM file is generated locally and ready to download in moments.
Will I lose quality converting MP4 to WebM?
Quality is preserved as closely as the WebM format allows. For most web video the result is visually identical to the source.
Does this work on mobile?
Yes — it runs in any modern browser on desktop or mobile, with nothing to install.