Convert WebM to MKV

Convert WebM to MKV locally for flexible containers and archiving.


WebM to MKV helps when you want a robust container for storage, library management, or broad desktop player compatibility.

If you need maximum device compatibility, use WebM to MP4. If you want a small web-first result, WebM is already optimized for that role.

Best for

  • Local archiving and collections
  • Desktop playback workflows (VLC-friendly)
  • Container flexibility for your media library

Why use Client Tools?

  • Privacy-First & Secure: All processing happens directly in your browser. We never upload your files to any server.
  • Corporate Grade Security: Ideal for handling sensitive documents, contracts, and NDA-protected images. Since data never leaves your device, it is impossible for third parties to intercept it.
  • No Limits: Convert as many files as you want, of any size (limited only by your device's RAM).
  • Fast & Offline Capable: Works instantly without waiting for network uploads.

How it works

Unlike other converters that require you to upload your files to a cloud server (which creates a privacy risk), Client Tools uses advanced WebAssembly technology to run professional image processing software directly inside your web browser.