Video
Turn your MKV files into WebM in seconds. Everything happens in your browser: nothing is uploaded to any server.
Drag your files here
Or paste them with Ctrl+V. They never leave your device.
Browsers, iPhones and many TVs do not play it. As WebM (VP9) it is lighter and plays directly in browsers.
MKV (Matroska) is an open container that accepts almost any codec, several audio tracks and subtitles.
Strengths: Very flexible: common for films and series with several languages.
Limits: Browsers, iPhones and many TVs do not play it.
WebM is an open, patent-free video format made for the web; here it comes out with VP9 video and Opus audio.
Strengths: It compresses very well and plays directly in Chrome, Firefox, Edge and recent Safari.
Limits: Editing programs, TVs and old phones often cannot open it.
No. The MKV to WebM conversion runs entirely in your browser, with code downloaded from this site and executed on your device. You can check it in the Network tab of the developer tools or by going offline after the page loads.
It depends on the length, the resolution and your computer. The browser’s hardware acceleration is used when available, and you get an estimate before it starts.
Up to 2 GB and 3 hours of video on desktop; on mobile, 500 MB and 30 minutes (AVI: 1 GB and 1 hour on desktop). If it is over, you are told before it starts and can trim it.
Yes. Drop as many MKV files as you like: several are converted at the same time, depending on your processor cores, and when they finish you can download each WebM or all of them in a ZIP.