Convert MKV to MP3
Get the sound from OBS recordings, films, and other MKV videos as an MP3.
Used by 500K+ people since 20215M+ minutes processed
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Free for the first hour, 10 times a day. No sign-up.
From MKV to MP3
Play MKV, then MP3.
MKV · 280 KBbecomesMP3 · 137 KB
How to convert MKV to MP3
- 1
Add an MKV, such as an OBS recording or a film.
- 2
Keep MP3, or pick WAV to edit the sound.
- 3
Download the MP3.
Inside an MKV file
MKV, short for Matroska, is an open format that can hold a picture, several sound tracks, subtitles, and chapters in one file. Films and anime often come as MKV with more than one sound track, such as two languages or a director's commentary. OBS Studio can record up to six tracks at once, such as your microphone on one and game sound on another, with Track 1 usually carrying the full mix.
Converting keeps one track, the first, whatever its sound is: AAC, AC-3, DTS, FLAC, Opus, or Vorbis. Use the MP3 to listen to a stream or a lecture without the video, to send someone a clip, or to bring a recording into an audio editor.
Questions
Which sound track do I get?
Always the first one, which is usually the main one. In an OBS recording, that's Track 1, which normally carries everything you heard. In a film with several languages, it's whichever the file lists first. You can't choose another track here: to get a dub or a commentary, save that track on its own in a video editor first.
Why record in MKV?
An MKV stays playable if the recording stops without warning, such as in a crash or a power cut, while an unfinished MP4 can be lost. That's why OBS's own guides suggest recording in MKV. Many phones and editors won't open one, but the MP3 plays anywhere.
What happens to surround sound?
A film's 5.1 sound comes out of the MP3 as stereo, so it plays on headphones, laptops, and phones. To keep every channel apart, pick WAV or FLAC under Convert to.
Can I keep the sound exactly as it is?
Yes, when the MKV's sound already is one of the formats here. AAC goes into an M4A, and FLAC or Opus into a file of its own kind, copied without being converted again.
Does it work on a whole film or a long stream?
Yes, up to 10 hours. Without an account, files up to 100 MB work, and a film is usually bigger, so sign in, free, for files up to 10 GB.
What about the subtitles?
They're left out, along with chapters and the picture: an MP3 holds only sound. For subtitles of what's said, Transcribe can make SRT captions from the MP3.
Is it free?
Yes, for the first hour of each file, 10 times a day, with no sign-up. For longer files, see pricing.
What happens to my files?
They stay private. Files are deleted after 24 hours, and free results after 1 hour.
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- Transcribe audioSpeech to text, who said what.
- Text to SRTSync a script to audio.
- Remove filler wordsCut the ums and uhs.
- Cut audioTrim start, middle or end.
For AI assistants and developers
Ask ChatGPT, Claude, or a coding agent to do this for you, or call it from your own code.
Show the free API call
curl -F file=@recording.mkv -F format=mp3 https://audo.ai/api/try/convert -D response.headers -o response.body