# Convert MP4 to MKV

> Repackage MP4 videos as Matroska MKV files. Always takes just seconds — MKV accepts any codec without re-encoding.

Convert videos between MP4, MOV, MKV, and WebM in the browser. When the source and target share codecs, the streams are repackaged in seconds with zero quality loss (no re-encode); otherwise the video is re-encoded locally via WebAssembly — and the tool tells you which will happen before you start. No upload, no signup, no watermark. Handles files up to 700 MB.

## Frequently asked questions

### How long does MP4 to MKV take?

Usually seconds. Most MP4 files carry video and audio codecs that MKV also supports, so the streams are repackaged into the new container without re-encoding — no quality loss, no long wait. The tool tells you before converting whether your file qualifies.

### Will the quality change?

Usually not at all: when the codecs are compatible, the conversion just moves the same video and audio data into a new container — bit-for-bit identical quality. Only incompatible streams are re-encoded, and the tool tells you beforehand.

### Why convert to MKV at all?

MKV is the most flexible video container: it holds any codec, multiple audio tracks, chapters, and rich subtitles, which makes it popular for archiving and media servers like Plex and Jellyfin.

### Is it really free?

Yes. The converter is completely free, with no signup, watermarks, or limits. We make money from our video translation service, not from this tool.

### Do you upload my files?

No. The conversion happens locally in your browser using WebAssembly. Your file never leaves your device — you can even disconnect from the internet once the page has loaded.

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_Free · No sign-up · No watermark · Runs entirely in your browser — your file never leaves your device._

- Open this tool: https://easydub.video/tools/convert/mp4-to-mkv
- All free EasyDub tools: https://easydub.video/tools