Video tool

Convert WebM Files to MKV on Your Device

Convert WebM to MKV in your browser for multi-platform libraries. The source remains on your device throughout local processing.

Route WEBM → MKV

or drop here · up to 500 MB

Preview (optional)

When your browser supports it, your video appears here. If preview does not load, you can still convert your file normally.

Ready

Use upload name

The device processor performs decoding and encoding during the job during this WebM-to-MKV job.
Available memory can limit very large WebM conversion jobs.
Compare the MKV duration with the source before publishing.

MKV serves flexible media libraries and archives, whereas WebM commonly serves web publishing and Chromium-based playback.
For WebM-to-MKV delivery, plan for rejection by some TVs and upload forms.
After leaving WebM, the receiving app must support the streams encoded inside MKV, not only its extension.

WebM to MKV taking too long? Try a small source first to separate a performance issue from a format issue.
MKV converted from WebM not opening? Test a compatible player and inspect the output streams.
A MKV extension alone may not be enough; verify the required internal codec.

When does WebM to MKV conversion make sense?

It is useful when WebM media created for browser delivery must enter a MKV system designed for multi-platform libraries.

Where is the WebM source processed?

The browser prepares MKV from WebM on this device instead of sending the source to a remote conversion server.

How can I approve MKV converted from WebM?

Test the MKV file in the receiving app and compare duration, picture, sound and timing with the WebM source.

Quick use cases