Convert MKV to WebM
Settings
No file yet
Settings appear after you choose a file.
An MKV that has to go onto a web page? Convert it to a WebM, the open video format made for embedding, and drop it into the page.
MKV or WebM?
Keep MKV when
- It is the original. Encoding it again loses a little detail.
Pick WebM when
- A website or an app asks for WebM files.
About MKV and WebM
MKV
A flexible video container that holds several audio tracks and subtitles in one file. Popular for films and screen captures.
WebM
An open video format made for the web. Common for screen recordings and clips saved from sites, less so in media players.
Questions
Does the WebM look worse?
A little. VP9 is lossy, so encoding the video again drops some detail. A lower CRF loses less.
Which codecs go in the WebM?
The Terminal lines write VP9 video and Opus sound. VLC's WebM profile writes VP8 video and Vorbis sound, which a WebM also takes.
Which CRF should I pick?
The commands use CRF 32 for VP9, a common middle ground between size and quality. Change -crf 32 to a lower number for a better picture and a larger file, or a higher one for a smaller file, 0 to 63.
Is there a copy line?
No. A WebM takes only VP8, VP9 or AV1 video, so an MKV with H.264 video has to be encoded again.
Can I convert a whole folder at once?
Yes. Drop them all here. In Terminal, one line converts every MKV in the folder.