Convert MKV to MP4
OBS saved your recording as MKV, and now your phone, TV or editor won't open it. Convert the MKV to MP4 in your browser. Nothing is uploaded and there is no signup.
- MP4
- MOV
- AVI
- VOB
- MKV
- WEBM
- MPG
- MPEG
- M4V
- 3GP
- TS
- MTS
- M2TS
- Runs in your browser
- 100% free
- Private
How to convert MKV to MP4
Drop in the MKV
Add the .mkv file from your OBS recordings folder, a download or a Blu-ray rip.
Convert to MP4
Click Convert to MP4. If the MKV already holds H.264 video and AAC sound, Adapterry moves them into an MP4 without re-encoding, which is quick. Otherwise the file is fully converted.
Preview and save
Play the MP4 on the page to check it, then download it.
Why people use Adapterry
Nothing is uploaded
Your videos are processed in your browser and never leave your device.
No account needed
Open the page and start. No email, no password.
No watermark
Your video comes out clean, with no logo stamped on it.
Works offline
Once the page and video engine have loaded, you can keep working without an internet connection.
Supported formats
Add MP4, MOV, AVI, VOB, MKV, WebM, MPG, M4V, 3GP, TS or MTS files, or a mix, and get back one MP4, MOV, AVI or VOB, or an MP3 of the sound. MP4 plays almost everywhere.
Why MKV files get refused
MKV (Matroska) is a container that can hold almost any video and audio, plus several audio tracks and subtitles. OBS saves recordings as MKV by default, and many downloads and Blu-ray rips use it too. Plenty of phones, TVs and editors don't accept it.
MP4 is the format nearly everything plays. When your MKV holds H.264 video with AAC sound, the conversion only repackages it, with no quality loss. HEVC video, or AC3 and Opus sound, are fully converted to H.264 and AAC instead. Only the first audio track is kept, and subtitles are not carried over.
Questions and answers
Why won't my OBS recording open on my phone?
OBS saves MKV files by default, and many phones, TVs and editors don't accept MKV. Converting the recording to MP4 fixes that, and the picture stays exactly the same when it is already H.264 with AAC sound.
Is MKV to MP4 a quick conversion?
Often, yes. An MKV with H.264 video and AAC audio is moved into MP4 without re-encoding, so it is fast and loses no quality. Other codecs, like HEVC or Opus, need a full conversion that takes longer.
What happens to the extra audio tracks in my MKV?
Only the first audio track goes into the MP4. If you recorded several tracks in OBS, or the file has several languages, the others are left out.
Are MKV subtitles kept in the MP4?
No. Subtitles are not carried over, so the MP4 has the picture and the first audio track only.
Can I convert a long gameplay recording?
Yes. There is no fixed size limit, but large files take minutes and use your device's memory. Keep the tab open until it finishes, and use a desktop computer for very long recordings.