MKV to MP4
Rewrap MKV videos as MP4s that phones, TVs and editors accept.
How it works
- 01Drop in your MKV video.
- 02MP4 is already selected. Leave the quality at "original" for a fast copy.
- 03Press Convert and download the MP4.
Questions
›Why won't my MKV play on my phone or TV?
MKV (Matroska) is a flexible container that many phones, smart TVs, editors and upload forms don't accept. MP4 is supported almost everywhere, even when the video inside is exactly the same.
›Is the conversion lossless?
Often, yes. If the MKV holds H.264 or HEVC video, it is copied into the MP4 untouched, which takes seconds. Other codecs, like VP9 or older MPEG-4, are re-encoded to H.264, which takes longer. Sound MP4 players handle badly, such as Opus or surround tracks, is converted to stereo AAC.
›What about subtitles and extra audio tracks?
Only the main video and audio track are kept. Subtitle tracks, extra languages and chapters are left out. To put subtitles back, burn them in with the add subtitles tool.
›Some MKVs won't open. Why?
If your browser can't decode a codec inside the MKV, we offer the one-time 31 MB ffmpeg decoder download to handle it. Files that are damaged or use very unusual codecs may still fail.
›Are my files uploaded anywhere?
No. Your files are processed on your own device by your browser. They never touch our servers, so there are no upload waits, no size caps from us, and nothing to delete afterwards.