MKV to MP4 converter
Make MKV files play on phones and streaming apps.
Runs in your browser. Your files never leave your device.
- Batch convert
- H.264 and AAC output
- Nothing uploaded
How to convert MKV to MP4
- Drop your MKV files here.
- Each one converts to MP4.
- Download the MP4 files.
What MKV can hold that MP4 can't
MKV, short for Matroska, is an open, patent-free container started in 2002. It was designed to hold almost any combination of video, audio and subtitle tracks, including several of each at once, which is exactly why it became the standard for ripped movies and TV shows with multiple language and subtitle options. MP4 is far more restrictive, which is why some MKV files won't open on phones or streaming apps that only understand MP4's narrower rules.
What the conversion keeps and drops
| Kept | Dropped | |
|---|---|---|
| Video | Re-encoded to H.264 | Nothing |
| Audio | One track, re-encoded to AAC | Extra audio tracks beyond the first |
| Subtitles | Nothing | All subtitle tracks |
If you need the subtitles kept, look for a dedicated subtitle extraction tool first and save them separately before you convert the video, since there's no way to recover them from the MP4 afterward.
MKV to MP4 FAQ
Why won't my MKV play on my phone or TV?
MKV is a flexible container often used for movies and shows, and it can hold almost any codec, but many phones, smart TVs and streaming apps only accept MP4.
Will the quality change?
Not if the MKV already holds H.264 video and AAC audio: those tracks are copied into the MP4 unchanged. Other codecs, such as HEVC, VP9 or AC-3 audio, are re-encoded to H.264 and AAC at a high quality setting.
What about subtitles inside the MKV?
Subtitle tracks are not carried over to the MP4. Extract them separately with a dedicated subtitle tool if you need them.
What about multiple audio tracks, like dubbed languages?
MKV files sometimes hold more than one audio track. This tool converts the video with a single audio track in the output; if you need a specific language track kept, that needs a desktop tool that can select it before converting.
How long does a large MKV take to convert?
An MKV with H.264 and AAC tracks is repackaged in seconds, even at movie length. Other codecs are re-encoded, and a full movie can then take several minutes depending on resolution and your device.
Can I convert several MKV files in one go?
Yes. Drop them all in and download each one, or grab them together as a ZIP.
Is my file uploaded?
No. The conversion happens in your browser, on your own device.