Convert images, documents, video and audio in your browser. Your files stay on your device.
Convert MKV videos to MP4 right in your browser, using your device’s hardware acceleration when available. You can also trim, resize or remove the audio.
Drag one or more MKV files onto the dashed area, or tap it to pick them from your device.
MP4 is already selected. If you want, open the options to trim the video or change its resolution or quality.
Press “Convert to MP4”. When it’s done, download the files one by one or all together in a ZIP archive.
Good to know. If the video is already compatible with the chosen format it’s copied without re-encoding: the conversion is very fast and the quality identical.
Source format
Matroska Video
An open, flexible container that accepts almost any codec, several audio tracks and subtitles. It’s loved for films and series, but TVs, iPhones and some editors can’t read it.
Target format
MPEG-4 Part 14
The most widespread video format in the world: phones, TVs, browsers and social networks all play it. It usually contains H.264 video and AAC audio, a pairing that gives good quality with compact files.
Audio and video use WebCodecs: they work in up-to-date Chrome, Edge, Opera and Samsung Internet, in Firefox 130+ and Safari 17+ (with a few limits on the formats they can create). If your browser can’t create the chosen format, we tell you before you start.
No. The conversion from MKV to MP4 happens entirely in your browser, using your device’s computing power. Files aren’t sent or stored anywhere: when you close the page they’re gone from memory too.
Up to 100 files at a time. There’s no fixed size limit: it depends on your device’s memory. On smartphones it’s best to work in smaller batches with heavy files such as videos.
Yes, with up-to-date Safari, Chrome, Firefox, Edge and Samsung Internet. On phones, converted files end up in the Downloads folder or the Files app.
Only to open the page (and, the first time, to download the components needed for that type of file). After that the conversion keeps working even if the connection drops.