MKV to MP4
Copies a matching H.264 stream when it can, or re-encodes to H.264 and AAC when it can't.
Drop an MKV video here
Everything happens on your device — your files are never uploaded.
Preview isn't supported for MKV in this browser. Conversion still works.
Done
How it works
- 1 Drop your MKV (Matroska) file or pick it from your device.
- 2 Hit Convert to MP4 and watch the progress bar.
- 3 Download the MP4. It plays on phones, TVs, and any editor.
Built with open source
- Mediabunny — Converts and edits video and audio in the browser via WebCodecs. Add-on encoders cover MP3, AAC, and FLAC. · MPL-2.0
Frequently asked
Does my MKV get uploaded to a server? +
No. Everything runs in your browser with WebCodecs. Your MKV never leaves your device. No upload, no watermark, no account.
Is the conversion lossless? +
If your MKV already holds H.264 video and AAC audio, the streams are remuxed straight into the MP4 container. That part is near-instant and pixel-for-pixel lossless. Other codecs like HEVC, AV1, and VP9 are re-encoded to H.264, which is a normal lossy step.
It says my browser can't encode H.264. What now? +
When the source has to be re-encoded, MP4 needs an H.264 encoder. Chrome and Edge have one. Firefox does not. Open this page in Chrome or Edge and try again.