Convert WebM to MKV Video

Convert WebM Open Media Format (WebM) video files into universally compatible Matroska Multimedia Container (MKV) format. Fast, private, and free with no file size limits or upload waiting times.

⚡ 100% In-Browser 🔒 Zero Server Uploads ✨ Full Quality Preserved

WebM vs MKV: Format Comparison

Feature WebM MKV
Compression Algorithm Lossy (Compact file size) Lossy (Compact file size)
Alpha Transparency Supported (Transparent background) Not Supported (White background)
Animation / Sequences Supported Supported
Browser Compatibility 98%+ (HTML5 Native across Chrome, Firefox, Safari, Edge) Requires conversion for browser playback
Ideal Application HTML5 web video, transparent video overlays, royalty-free web streaming High-definition movie rips, multi-language subtitle tracks, lossless audio containers

How to Convert WebM to MKV (3 Easy Steps)

  1. Upload WebM: Select your WebM file by dragging and dropping it into the conversion box, or click Browse to choose from your device.
  2. Select MKV Output: Configure your output parameters. The tool is pre-set to convert to MKV. Adjust quality or dimension preferences if required.
  3. Instant Download: Click Convert and download your finished MKV instantly. Everything processes locally in your browser memory.

Technical Specifications

About WebM

Full Name: WebM Open Media Format

MIME Type: video/webm

Developer / Standard: Google LLC

Developed by Google as an open-source, 100% royalty-free video container for HTML5.

About MKV

Full Name: Matroska Multimedia Container

MIME Type: video/x-matroska

Developer / Standard: Matroska Project (Steve Lhomme)

Named after Russian Matryoshka nesting dolls due to its ability to hold limitless video, audio, and subtitle streams.

Frequently Asked Questions

How do I convert WebM to MKV?

Upload your WebM video, adjust frame size or quality if desired, and click Convert. The video is rendered directly in your browser using WebAssembly FFmpeg.

Is there a file size limit for WebM conversions?

Because processing runs locally on your computer rather than remote cloud servers, you are not bound by typical 100MB server upload caps.

Can I play MKV on all devices?

Requires conversion for browser playback

Related Conversion Tools

MP4 → WEBMMP4 → MOVMP4 → AVIMP4 → MKVMP4 → GIFWEBM → MP4