Convert WEBM to MKV — Free & Private
Convert WEBM to MKV online for free. WEBM is an open-source video format for the web; MKV is a flexible container format that supports multiple streams. All processing happens locally in your browser — your files never leave your device.
How to convert WEBM to MKV
- 1
Select your WEBM file
Click or drag your WEBM file onto the converter above.
- 2
Convert to MKV
The output format is pre-set to MKV. Click the convert button to process your file.
- 3
Save instantly
Your converted MKV file is ready — save it to your device, no email required.
WEBM to MKV — FAQ
Is the WEBM to MKV converter really free?
Yes, completely free. No hidden fees, no watermarks, no file size limits. LocalConvert is open source and free forever.
Are my WEBM files safe?
Absolutely. Your files never leave your browser. All WEBM to MKV conversion happens using WebAssembly running locally on your device — no uploads, ever.
How long does WEBM to MKV conversion take?
Most conversions finish in seconds. Larger files may take a little longer depending on your device's speed and memory.
What's the difference between WEBM and MKV?
WEBM is an open-source video format for the web. MKV is a flexible container format that supports multiple streams.