Convert MKV to MP3
Get the sound from OBS recordings, films, and other MKV videos as an MP3.
10M+ files processed since 2021
More options
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
Audo's MKV to MP3 converter pulls the sound out of OBS recordings, films, and other MKV files up to 10 GB without an account, free for the first hour of each, 10 times a day. A 3-minute clip usually takes about 4 seconds.
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.
How do I extract audio from an MKV?
Audo's MKV to MP3 page is an MKV audio extractor: add the MKV at the top and download the MP3. To edit the sound, pick WAV under Convert to first. To keep it exactly as it is, pick the kind it already is: M4A for AAC, or FLAC or Opus for those, copied without being converted again.
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.
Is there a free MKV to MP3 converter?
Yes. Audo converts the first hour of each MKV free, 10 times a day, with no sign-up. Files up to 10 GB work without an account, and up to 10 hours when signed in; full-length recordings are $0.01 a minute ($0.60 an hour) with no subscription (see pricing).
Can I turn an MKV into an MP4 here?
No. This page keeps only the sound; the picture, subtitles, and chapters are left out. For subtitles of what's said, Transcribe can make SRT captions from the MP3.
What happens to my files?
They stay private. Files are deleted after 24 hours, and free results after 1 hour.
More tools
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- Remove noiseClears the background, keeps your voice.
- Remove echoMake voices sound close.
- Vocal removerSeparate vocals, music, and stems.
- Stem splitterSplit vocals, drums, and bass.
- Karaoke makerRemove vocals, keep the music.
- Change pitchMove the key up or down.
- Change speedSpeed up or slow down audio.
For AI assistants and developers
Ask ChatGPT, Claude, or a coding agent to do this for you, or call it from your own code. When an agent's free result is cut short, it gives you a link to finish the whole file, no sign-up.
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