What is a MKV file?
MKV — Matroska
Use the format MKV
A concrete example
Prepare an MP4 copy for a device that does not play MKV.
Useful checks
Check languages, subtitles, and chapters. Changing the container does not guarantee keeping all tracks.
Choose a conversion
Keep the original and open the result in the software or on the device that will need to use it.
Your questions about this format
How to choose between MP4, WEBM, and MKV?
MP4 is suitable for many sharing purposes; WEBM is particularly intended for web playback. MKV may be better suited for content with multiple tracks. Look at the outputs offered for your file and test the result on the player you will actually use.
Can I extract only the audio from my video?
Yes, if MP3 is listed among the outputs of your source. Add the video, choose MP3, and start the conversion. The file must contain an audio track: a silent video cannot produce a sound recording.
Why am I being offered MKV for tracks and subtitles?
Not all outputs retain the same tracks. If the engine indicates that a MKV container is required, go back to the output selection and choose MKV instead of forcing a conversion that would remove elements. This output may fall under NoLimit.
How many videos can I convert for free?
The free offer allows one video per day, within the total quota of ten files and the limit of 100 MB per file. A batch of three files does not add three video rights: the video quota remains shared. A valid NoLimit access adjusts the limits according to the displayed offer.
What is it?
MKV is the most flexible container format available. A single file can hold several video tracks, a dozen or more audio tracks in as many languages, multiple subtitle tracks, chapters, thumbnails, and embedded fonts.
This versatility has made it the go-to format for movies and TV series: the original version, the dubbed version, and every subtitle track can live in one file, selected on the fly during playback.
History & origin
The Matroska project began in 2002, launched by a French developer with a clear goal: build an open, extensible, patent-free container to overcome the limitations of AVI.
The name comes from Russian nesting dolls, a nod to its structure of boxes within boxes. Google's WebM is directly derived from it.
Why it is useful
Unmatched flexibility: unlimited tracks, embedded subtitles, chapters, and rich metadata.
An open, royalty-free format that's also resilient — a partially downloaded MKV file often still plays.
Limits & drawbacks
Hardware compatibility is its weak point: Apple devices don't support it natively, and many TVs won't play it either.
No web browser can display it directly.
Practical tips
MKV is ideal for building a personal media library played on a computer or a media player box.
To play a video on an iPhone or TV, or to send it to someone, convert it to MP4. The conversion is often quick: if the internal codec is already H.264, the process just repackages the file without recompressing the video.
Convert your MKV in seconds, on our secure servers in France.
Convert a MKV