WEBM to MKV Video Converter
Drop your WEBM files — the MKV video is generated in your browser in seconds. Multiple files at once, no upload on the fast path.
9,214+ video files converted
Need your video as MKV? Drop the files and they are re-encoded right on this page — no install, no sign-up, no queue. Typical MKV output is Varies, and the work happens locally so your video stays on your machine.
Looking to programmatically convert WEBM to MKV?
Same engine, available as a JSON API. Drop a file or URL via REST and get the converted video back — no browser, no UI, no rate limits on paid tiers.
Fast response on common video pairs
Webhook delivery for batch jobs
Dozens of video format pairs supported
WEBM vs MKV: how they compare
The numbers and capabilities at a glance, so you know what you're trading.
WebM
- Year released
- 2010
- Compression
- VP9 (lossy)
- Transparency
- Yes (alpha)
- Animation
- Yes (video)
- Browser support
- Modern browsers
- Best for
- Web embedding, open source
MKV
- Year released
- 2002
- Compression
- Codec-dependent
- Transparency
- Codec-dependent
- Animation
- Yes (video)
- Browser support
- Players, limited browsers
- Best for
- High-quality archives
Heads up before converting to MKV
What this specific conversion changes about your video.
Lossless when the codecs already fit
If your WEBM uses codecs MKV accepts, we remux (rewrap) it losslessly and instantly. A codec change re-encodes, which recompresses slightly.
Best practices for MKV
Small choices that keep your output sounding right.
- Play the MKV result back before deleting your original WEBM.
- Pick a preset (Web, Mobile, High quality) to balance size and quality for your MKV.
The importance of a good video conversion
Why getting WEBM → MKV right matters more than you think.
Convert WEBM to other formats
Convert other formats to MKV