Convert MKV to MP4.
MKV into universal MP4 — converted right in your browser.
Drop MKV files here
or browse your files
Paste with ⌘V · or drop files anywhere on the page
Files never leave your device. Everything runs in your browser, nothing touches a server — tools you've used even work offline.
Convert MKV files to MP4 entirely in your browser — the video is re-encoded and the audio carried over or converted, with nothing uploaded anywhere. MKV is a flexible format, but phones, TVs and editors often refuse it; MP4 opens everywhere. If your browser cannot read the video inside, the tool tells you straight away.
How it works
- Drop files anywhere on the page, click to browse, or paste with ⌘V.
- Pick a quality or preset — or set an exact target size and let the tool find it.
- Compress, compare before/after, and download — individually or as a ZIP.
Why players reject MKV
MKV is a favorite of archivists because it can hold practically anything — several audio tracks, subtitles, any codec. That same flexibility is why phones, TVs and editors often refuse it: they cannot rely on what is inside. MP4 with H.264 makes the contents predictable, which is the whole point of converting.
Big files welcome
MKV files tend to be large, and with an upload-based converter a multi-gigabyte file spends longer travelling than converting. Here there is no travel: conversion starts the moment you drop the file, bounded only by your device. If the result should also be smaller, Compress MP4 finishes the job.
Frequently asked questions
Why convert MKV to MP4?
MKV is a powerful format loved by rippers and archivists, but phones, TVs, editors and upload forms often reject it. MP4 with H.264 is the safe, universal choice.
Which MKV files work?
Any whose video your browser can play — the vast majority of MKV files (H.264, HEVC, VP9, AV1) work. If one is not supported, you get a clear error instead of a broken file.
Can I shrink the file while converting?
Yes — pick a lower quality or switch to target-size mode and enter a limit like 25 MB; the converter fits the file to your budget.
Is anything uploaded?
No. Encoding runs on your own hardware from first frame to last — nothing streams to a server, which is also why there is no file-size cap and no queue. Close the tab and every trace of the footage is gone. Want proof? Run one file through, switch your connection off, and run another — it still works.