MP4 to WebM Converter
Make WebM videos for your website, right in your browser.
Free · No upload · No sign-up · No watermark
How to convert MP4 to WebM
- 01
Open your MP4
Drop the MP4 — or any other video.
- 02
Keep WebM selected
Choose VP9 (plays everywhere) or AV1 (smaller, where your browser can make it).
- 03
Convert and download
The picture is encoded on your device, with Opus sound.
Why use Cutlia for this
VP9 or AV1
VP9 plays in every modern browser; AV1 packs the same picture into fewer bits.
For websites
WebM is made for <video> on the web — open formats, free of licensing.
Opus sound
The sound is encoded to Opus, WebM's standard audio codec.
Frequently asked questions
VP9 or AV1?
VP9 if you want it to play everywhere; AV1 for smaller files on newer devices. AV1 is offered only where your browser can encode it.
Can I make the WebM smaller?
Pick a lower resolution here — or use Compress Video to aim for a file size.
Is my video uploaded to a server?
No. Cutlia processes your video directly in your browser using WebAssembly and your device's hardware. The file never leaves your computer or phone, so it stays completely private.
Is it really free?
Yes. Cutlia is free to use with no account, no trial and no watermark on your export. The site is paid for by the ads on it, and your files never leave your device.
Popular conversions
Each is this converter with the format already picked — and it still opens any video.