MKV to MP4 free

MKV is a container, not a video format, and most MKV files already hold H.264 video that phones, TVs and editors would play happily if it were in an MP4. This converter repackages the stream into MP4 on your device, usually in seconds and without touching quality; only files with unusual codecs are re-encoded.

Drop a video here MP4, MOV, WebM, MKV, 3GP · up to a few GB on a laptop, ~500 MB on a phone · nothing is uploaded

Choose a video

Remux, not re-encode

When the MKV holds H.264 or H.265 video and AAC audio, the streams are copied into an MP4 unchanged. No quality loss, no long wait.

No upload, no limit

A 4 GB file converts on your own machine. Nothing goes to a server, so there is no size cap or queue.

Falls back when needed

VP9, AV1 or unusual audio tracks are re-encoded to H.264 and AAC so the MP4 plays everywhere.

Frequently asked questions

Why is it so fast?

Because nothing is re-encoded. The video and audio streams are moved from the MKV container into an MP4 container, which is a file-copy-sized job.

Subtitles and multiple audio tracks?

The first video and audio track are kept. Soft subtitles in the MKV are not carried into the MP4; burn them in with an editor if you need them.

Will it play on an iPhone or TV?

Yes if the result is H.264 and AAC, which is the default for anything that had to be re-encoded. H.265 MKVs are remuxed as H.265 MP4, which modern devices play.

Is anything uploaded?

No. The file is processed in your browser on your own device. Nothing is sent to a server, nothing is stored, and it works offline once the page has loaded.