What is an MKV file?
MKV, short for Matroska, is a flexible open container. It can hold several audio tracks, many subtitle tracks and chapters in one file, which is why it is popular for downloaded films, series and long recordings.
That flexibility is also its weakness. Many TVs, phone galleries, social networks and editing programs handle MP4 much better than MKV, so people convert to MP4 when the file will not play or will not upload.
How to convert MKV to MP4
- Drop your MKV file on the page.
- In the Convert tab, make sure MP4 is selected.
- Press Start and wait until the progress bar is full.
- Play the preview, check sound and subtitles, then download.
Before you convert
MP4 does not treat extra audio tracks and subtitles as flexibly as MKV. After the conversion, check that you hear the language you want and that any subtitles you need are still there.
MKV files are often large. If the MP4 is still too heavy for your use, the Compress tool can reduce the resolution or aim for a size in megabytes. The Trim tool lets you keep only the part you need.
Questions
Will I keep my subtitles?
Check the result. MP4 does not support every subtitle type the way MKV does, so some may not carry over.
Is the quality reduced?
The video is encoded again, so a small difference is possible. Keep your MKV until you have checked the MP4.
Can I convert a large MKV movie?
It works while your computer has enough free memory. Very large files, above roughly 1.6 GB, may be too much for a browser.