Convert MKV to WebM Online
Turn MKV files into WebM directly in your browser using ConverterUp. There is no upload, no waiting in a queue, and no account required — your files stay on your device while WebAssembly does the work locally. Adjust quality and dimensions where supported, then download the result. The output keeps the visual fidelity you'd expect from a desktop app while running entirely in the browser tab.
Convert MKV to WebM nowHow to convert MKV to WebM
Open the converter
Click the button to open the MKV to WebM tool. It loads instantly — no install, no signup.
Drop your MKV file
Drag your MKV file into the upload area or click to browse. The file stays in your browser memory only.
Download WebM
The conversion runs locally and finishes in seconds. Click download to save the WebM file to your device.
Frequently asked questions
Is the MKV to WebM conversion really free?
Yes. ConverterUp is fully free, with no signup, no watermarks, and no daily quota for the MKV to WebM converter. We support the project through unobtrusive ads.
Are my MKV files uploaded to a server?
No. Conversion runs in your browser using WebAssembly. The MKV bytes never leave your device, and we have no upload endpoint at all.
What is the maximum file size?
For MKV input, the soft cap is 50 MB for images and 500 MB for video. Practical performance depends on your device's RAM.
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Ready to convert MKV to WebM?
Open the tool, drop your file, and download the result. No upload, no signup, no watermarks.
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