WEBM to MKV converter

Convert WEBM to MKV for free, with no sign-up and no paywall after upload.

Choose WEBM files or drop them here · paste a link below

Converted on our server · deleted after 60 min · Free limits

Where it runs: Our server, files deleted in 60 min
Free allowance: 25 files a day, up to 200 MB each
Typical time: Seconds to re-wrap; about the playing time to re-encode
Sign-up: Not needed

What happens to your WEBM

If the video is already H.264 or HEVC, we re-wrap it into MKV without re-encoding. That takes seconds and loses nothing.

Otherwise the video is re-encoded with settings that look the same as the original at a sensible file size. Large videos take roughly as long as they play.

This conversion runs on our server. Your file is deleted within 60 minutes, and you can delete it yourself as soon as you have downloaded the result.

How to convert WEBM to MKV

Choose your file Tap Choose files and pick the WEBM file, or drop it onto the page. You can add several at once.
Convert to MKV Tap Convert. The file is sent over an encrypted connection and converted on our server.
Download Tap Download to save the MKV file. It is deleted from our server within 60 minutes, or straight away if you tap Delete.

What is a WEBM file?

Google's open web video format (VP9 or AV1). Screen recorders and browsers produce it; iPhones and editors often cannot open it.

Chrome, Firefox, Edge and VLC play WEBM.

More about WEBM files

What is an MKV file?

A flexible open container that can hold many audio tracks and subtitles. Common for films and screen recordings from OBS.

VLC, MPV and Plex play MKV. iPhone, Safari and many TVs do not.

More about MKV files

Questions

Is converting WEBM to MKV free?

Yes. You can convert up to 25 files a day on our server for free, each up to 200 MB, with no sign-up. The limit is shown before you upload, and we never ask you to pay to download a file you have already converted.

Is it safe to convert my WEBM files here?

Yes. Files travel over an encrypted connection, are processed on our own server, and are deleted within 60 minutes. Nobody looks at them, and you can delete them yourself straight after downloading.

How long does WEBM to MKV take?

Seconds to re-wrap; about the playing time to re-encode. Bigger files take longer, and you can watch the progress on each file.

Can I convert WEBM to MKV on my iPhone or Android phone?

Yes. The converter works in Safari, Chrome and any modern browser. Tap Choose files, pick from Photos or Files, and download the result to your phone.

How do I open an MKV file?