MKV to WebM Converter
Convert MKV to WEBM online for free. MKV to WebM in seconds — no software install, no watermark, secure and fast.
Drag & drop your MKV file here, or
How to convert MKV to WebM in 3 steps
- 1
Upload your MKV file
Drag and drop or select the MKV file you want to convert.
- 2
Choose WebM as output
The output format is pre-selected for you — just confirm and start the conversion.
- 3
Download your file
Once processing finishes, download your converted WebM file instantly.
Benefits of converting MKV to WebM
Get royalty-free
Switching from MKV to WebM means your file now offers royalty-free, highly optimized playback for the web.
Wider compatibility
MKV is great for support for multiple audio/subtitle tracks and near-lossless quality, but not every app or device handles it well. Converting to WebM sidesteps that, so the file opens wherever you need it to.
No quality compromise
ConvertFastHub runs FFmpeg at production settings, preserving as much of the original MKV fidelity as the WebM format allows.
Keep your original too
Converting doesn't touch your source file — you get a brand-new WebM file back and can keep both versions.
Frequently asked questions
- How do I convert MKV to WebM online?
- Upload your MKV file above, select WebM as the output format, and click Convert. ConvertFastHub processes the file in the cloud and gives you a download link — no software installation required.
- Is it free to convert MKV to WebM?
- Yes. Free accounts get 10 conversions every 24 hours with files up to 50MB. For unlimited conversions, larger files up to 1.5GB, and priority processing, upgrade to ConvertFastHub Pro.
- What's the advantage of WebM over MKV?
- WebM offers royalty-free, highly optimized playback for the web. Meanwhile, MKV is known for support for multiple audio/subtitle tracks and near-lossless quality, ideal for archiving — the right choice depends on where you plan to use the file.
- Will converting MKV to WebM reduce quality?
- ConvertFastHub uses production-grade engines (FFmpeg, LibreOffice, ImageMagick) configured for maximum fidelity. Some format conversions are inherently lossy by design; where possible, we preserve the original quality.
- Is my file safe when I convert it?
- Files are uploaded over an encrypted connection directly to storage, processed in an isolated sandboxed worker, and permanently deleted within 24 hours.