WEBM to MKV Converter (.webm to .mkv)

Convert WebM Open Media Container (VP9 / Opus) (.webm) files to Matroska Multimedia Container (.mkv) directly on your device. WEBM is commonly used for html5 background videos, browser screen recordings, discord clips, and lightweight web embeds, while MKV is ideal for remuxing obs studio recordings to mp4 for premiere/davinci resolve or extracting audio tracks. Every conversion runs locally in your browser with zero server uploads.

100% On-Device Processing • Files Never Leave Your Browser (0 KB Uploaded)

Why Convert WEBM to MKV Locally?

Convert browser recordings and private clips without uploading gigabytes to remote servers. Unlike cloud converters that upload your .webm files to remote servers, Artoons processes your files directly on your device.

How to Convert WEBM to MKV

  1. Select or drag and drop your .webm (WEBM) file into the converter above.
  2. Confirm MKV (.mkv) as the target format and choose your preferred quality preset.
  3. Click Convert to automatically download your converted .mkv file.

Frequently Asked Questions

Do my WEBM files ever get uploaded anywhere?

Never — 100% of the conversion runs locally inside your own device memory with 0 KB sent over the network.

Will WEBM to MKV look or sound worse?

Quick heads-up: WEBM keeps see-through backgrounds, whereas MKV doesn't — transparent areas get filled with a clean solid backdrop. You can also tweak output quality in Preferences anytime.

How big of a .webm file can I convert here?

Right in this browser tab, you can convert .webm files up to 200 MB per file. Pushing bigger clips or giant folders? Grab the free Artoons Desktop App for unlimited sizes.

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