MP4 to WebM converter
Turn MP4, the most widely supported video format, playable on every phone, browser and TV, into WebM, an open web video format, common for screen recordings and browser captures. Free, private and fast: everything happens in your browser.
How it works
- 01
Drop your files
Videos, audio, images, or a whole folder. Nothing is uploaded: the files are read straight from your disk.
- 02
Pick a format
Choose a target for each type, or tap a preset like “Small video to share”. Tune size and quality if you want.
- 03
Save the results
FFmpeg runs in your browser. Preview each file, see how much space you saved, and download one by one or as a ZIP.
MP4 to WebM: questions
How do I convert MP4 to WebM?
Drop your MP4 files into the box above, check that WebM is selected, and press Convert. When it finishes, save each file or download them all as a ZIP.
Is it safe to convert MP4 files here?
Yes. Your MP4 files are converted on your own device by FFmpeg running in the browser. Nothing is uploaded to a server.
Is it free? Is there a file size limit?
It is completely free with no sign-up and no watermark. The only limit is your device’s memory: a few hundred MB per file works well on most computers. Very large videos may run out of memory in the browser.
Can I convert many files at once?
Yes. Drop a whole batch or pick a folder. Each type of file can go to its own format, for example images to WebP and videos to MP4, and you can download everything as one ZIP that keeps your folder structure.