Is MKV to MP4 free? Is there a watermark?

Yes — MKV to MP4 is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.

Do my files get uploaded to a server?

No. MKV to MP4 runs entirely in your browser with WebAssembly, so your MKV (Matroska) file never leaves your device and nothing is stored or seen by us.

What can I put in, and what do I get out?

MKV to MP4 accepts MKV (Matroska) and gives you back a MP4 file. Actual codec support depends on what the bundled engine or browser decoder can read.

Will I lose quality converting to MP4?

The H.264 conversion is lossy rather than a reversible container change. Keep the source and compare motion, fine text, colour, and audio sync in the result.

Free tools · Convert

MKV to MP4

Convert an MKV video into H.264/yuv420p MP4 with AAC audio for common playback and sharing workflows. Extra MKV tracks are not selected. Browser-only.

Runs entirely in your browser. Your file is never uploaded — no watermark, no account.

Drop a file or click to chooseMKV (Matroska)

Get a better result

Best for: Turning a Matroska video into a mainstream MP4 when the primary picture and sound matter more than MKV-specific extras.
Input → output: The default MKV video and audio streams become H.264/yuv420p video and 128 kbps AAC audio inside an MP4 container.
Quality tip: Test the primary video and audio pair on a short file before committing browser memory and time to a long source.
Know before running: Subtitle selection, chapters, attachments, alternate audio, HDR signalling, and multiple video tracks are not exposed. Those Matroska features should be preserved with a dedicated desktop workflow instead.
Next step: Remove metadata to reduce copied container information before sharing the converted file.

How to use MKV to MP4

1
Choose your file. Drop a supported MKV (Matroska) file into the tool, or click to select one. It stays on your device — nothing is uploaded.
2
Run locally. Press Run to begin. The first processing run loads the browser engine before local processing begins.
3
Download. Review the result, then download the finished file from your browser with no watermark.

Frequently asked questions

Is MKV to MP4 free? Is there a watermark?: Yes — MKV to MP4 is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.
Do my files get uploaded to a server?: No. MKV to MP4 runs entirely in your browser with WebAssembly, so your MKV (Matroska) file never leaves your device and nothing is stored or seen by us.
What can I put in, and what do I get out?: MKV to MP4 accepts MKV (Matroska) and gives you back a MP4 file. Actual codec support depends on what the bundled engine or browser decoder can read.
Will I lose quality converting to MP4?: The H.264 conversion is lossy rather than a reversible container change. Keep the source and compare motion, fine text, colour, and audio sync in the result.