How do I convert MP4 to MKV online?

Go to morph.cool, drop your MP4 file, select MKV as the output format, and download your converted file. The conversion happens in your browser — your file never leaves your device.

Is it safe to convert MP4 to MKV online?

Yes. Morph uses WebAssembly to convert files directly in your browser. Your file never touches a server. No upload, no storage, no risk.

Yes. Everything that runs on your device is free with no limits — every converter and every tool, including background removal. AI generation and work that runs on Morph's servers is paid in credits.

Convert MP4 to MKV Free Online — Morph

Convert MP4 to MKV instantly in your browser. No upload needed — your video stays on your device. Fast, free, and 100% private. Works on desktop, iPad, and mobile.

Visit morph.cool to convert files free.