Convert WebM to MKV
Free and instant — your WebM files are processed securely on our servers and deleted right after conversion. Nothing is stored.
How to convert WebM to MKV
- Step 01
Add your WebM files
Drop them into the box above or click to browse. You can add several files at once.
- Step 02
Conversion starts instantly
Your file is sent to our servers, converted and deleted right away — no sign-up, no queue, no waiting.
- Step 03
Download your MKV files
Save each file individually or grab them all at once. Done.
Why convert WebM to MKV?
Archiving a WebM download alongside a media library? Converting to MKV gives you a flexible open container that can hold multiple audio tracks and subtitles, and is the standard format for media server software.
WebM vs MKV at a glance
WebM is the open web video format — smaller than MP4 at the same quality, royalty-free and supported by every modern browser. MKV is the flexible open container — can hold almost any codec, multiple audio tracks and embedded subtitles, but browser support is limited.
| Property | WebM | MKV |
|---|---|---|
| Extension | .webm | .mkv |
| Full name | WebM Video | Matroska Video |
| First released | 2010 | 2002 |
| Developed by | Matroska project | |
| Compression | Lossy | Lossy |
| Transparency | No | No |
| Animation | No | No |
| Best for | web video — open format supported natively by all browsers | high-quality video with multiple audio tracks and subtitles |
WebM to MKV — frequently asked questions
Is this WebM to MKV converter really free?
Yes — completely free, with no sign-up, no watermarks and no daily limits.
Will I lose quality converting to MKV?
MKV uses lossy compression, so the image is re-encoded at high quality (92%). For photos the difference is practically invisible; for text-heavy graphics or logos, a lossless format like PNG preserves sharp edges better.
Is the conversion private?
Video conversion runs on our servers with ffmpeg — your file is deleted immediately and never stored.
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