Convert WEBM to MKV
Convert your WEBM video files to MKV directly in your browser.
How to convert video in 3 steps
Choose a WEBM video file.
Click convert to MKV.
Download your MKV video.
Format descriptions
WEBM — WebM is an open video container designed for the web. It uses VP8/VP9 and Opus codecs, offering small files and efficient streaming.
MKV — MKV (Matroska) is a flexible open-source video container that supports multiple video, audio and subtitle tracks in a single file.
Technical comparison: WEBM vs MKV
Technical breakdown of the WEBM and MKV specifications: compression, colour, transparency and animation support.
| Property | WebM | MKV |
|---|---|---|
| Specification | WebM (WebM Video Container) | MKV (Matroska Multimedia Container) |
| Media type | Video | Video |
| Compression | Hybrid (lossy or lossless) · VP8 / VP9 / AV1 + Opus | Hybrid (lossy or lossless) · H.264 / HEVC / VP9 / AV1 |
| Color space / bit depth | YUV 4:2:0 | 8/10/12-bit HDR |
| Transparency | Partial support | Not applicable |
| Animation | Yes (animated) | Yes (animated) |
| Best for | WebM is an open video container designed for the web. It uses VP8/VP9 and Opus codecs, offering small files and efficient streaming. | MKV (Matroska) is a flexible open-source video container that supports multiple video, audio and subtitle tracks in a single file. |
What happens when converting WEBM to MKV?
The WEBM data is decoded inside your browser with WebAssembly and re-encoded to the MKV specification, so no file is ever uploaded to a server. Both formats rely on comparable compression, so file size and perceived quality stay in the same range.
Frequently Asked Questions
What is video conversion?
Video conversion changes a video file from one format to another, for example from WEBM to MKV, while keeping the video content.
Are my video files uploaded?
No. This tool processes video files directly in your browser. Your video files are never sent to a server.
Which video formats are supported?
This tool converts WEBM video files to MKV, all in your browser.
Is it really free and unlimited?
Yes, the tool is completely free and you can convert as many video files as you want, with no limits.
Does it work on mobile too?
Yes, it works on any modern device, including smartphones, tablets and desktop computers.
Which format will the result be in?
The converted file will always be in MKV format, ready to download and use.
About the video converter
Convert WEBM to MKV video online for free. Everything happens in your browser: your files are never uploaded to a server, and you need no downloads or sign-up to get started.
See also:
- Video Converters
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- Convert WEBM to MP4Convert WEBM to MP4 video online for free. Everything happens in your browser: your files are never uploaded to a server, and you need no downloads or sign-up to get started.
- Convert WEBM to AVIConvert WEBM to AVI video online for free. Everything happens in your browser: your files are never uploaded to a server, and you need no downloads or sign-up to get started.
- Convert MKV to WEBMConvert MKV to WEBM video online for free. Everything happens in your browser: your files are never uploaded to a server, and you need no downloads or sign-up to get started.