Convert WEBM to MKV
Free, fast and secure — convert WEBM to MKV right in your browser.
Convert WEBM to MKV with a solid background
Converting WEBM to MKV flattens transparency onto a solid background, producing a Matroska video that displays consistently wherever transparency is not supported.
How to convert WEBM to MKV
- 1 Drop your WEBM file into the converter above.
- 2 It is converted to MKV automatically — no settings to fiddle with.
- 3 Download your new MKV file instantly.
WEBM vs MKV
| Feature | WEBM | MKV |
|---|---|---|
| Compression | Lossy | Lossy |
| Transparency | Yes | No |
| Animation | Yes | Yes |
| MIME type | video/webm | video/x-matroska |
| Best for | Embedding fast-loading video on websites and web apps. | Archiving high-quality video with multiple tracks — converted to MP4 for everyday playback. |
About the formats
WebM video
WebM is an open, royalty-free format built for the web. It streams efficiently in modern browsers and supports transparency, making it a favourite for HTML5 video.
Strengths
- Optimised for web streaming
- Open and royalty-free
- Supports alpha transparency
Limitations
- Limited support outside browsers
- Not ideal for editing
- Less common on mobile apps
Best for: Embedding fast-loading video on websites and web apps.
Matroska video
MKV (Matroska) is a flexible open container that can bundle many video, audio and subtitle tracks in one file. It is popular for high-quality archives and media libraries.
Strengths
- Holds multiple audio/subtitle tracks
- Open and future-proof
- Great for high-quality storage
Limitations
- Not supported on many phones/browsers
- Often needs converting to play
- Larger than streaming formats
Best for: Archiving high-quality video with multiple tracks — converted to MP4 for everyday playback.