All tools

MKV to WebM

Turn a Matroska MKV into a web-friendly WebM.

Uses your browser codecs

Local video benchNo file loaded
OutputWebCodecs

Speed depends on your device.

How it works

  1. Choose an MKV video.
  2. Keep WebM as the output.
  3. Convert and download the WebM.

MKV to WebM, briefly

MKV (Matroska) is a flexible container common for downloads and archived video, but browsers and web pages rarely play it directly. WebM is actually a restricted subset of Matroska built for the web, so it is the natural web-friendly target: modern browsers play it inline, and VP9 or AV1 keeps the file small.

Convert to WebM for embedding on a page you control. If you need broad compatibility for sharing or editing instead, target MP4 with the MKV to MP4 tool. See the MP4 vs WebM guide for the difference.

Questions

Why convert MKV to WebM?
Browsers do not play MKV directly, and WebM is the web-friendly Matroska subset. Converting gives you a small file that plays inline on a modern web page you host.
WebM or MP4 for an MKV?
WebM for self-hosted web video in modern browsers; MP4 when you need to share, upload, or edit, since WebM is not accepted everywhere.
Does it lose quality?
A small amount — re-encoding into a new codec is lossy. Converting once is usually invisible; re-encoding the same clip repeatedly is what adds up.
Why might an MKV fail?
MKV files can hold many track types, and conversion depends on your browser's codec support. An unusual or unsupported track can stop it; trying MP4 sometimes works instead.
Is the MKV uploaded anywhere?
No. The conversion happens entirely in your browser, so the file never leaves your device.