Convert MKV to MP3
MKV files often carry surround sound in AC-3, DTS or FLAC. The default audio track is decoded and mixed down to stereo MP3, ready for any player.
- Nothing is uploaded
- Free, no sign-up, no watermark
- Works offline once loaded
Drop a video here
or choose a file, or paste
MKV, MP4, MOV, WEBM, AVI, M4V, 3GP, FLV, WMV and more
Processed on your device. Nothing is uploaded.
Need more audio work, like noise reduction, EQ or batch conversion? Continue in Aback Audio. Open Aback Audio
How to use Extract Audio
- 1
Add the video
Drop an MP4, MOV, WebM or any other video on the drop zone.
- 2
Choose a format
Under Format pick MP3, M4A, WAV, OGG, FLAC or Opus.
- 3
Set the bitrate
For MP3, M4A, OGG and Opus choose a Bitrate; 192 kbps is recommended. WAV and FLAC are lossless and have no bitrate setting.
- 4
Extract and download
Press Extract audio, play the result to check it, then Download.
Why use Aback Video for this
Lossless copy when possible
Most MP4 and MOV videos carry AAC audio. Choosing M4A copies that track exactly, with no quality loss and almost no wait.
Six formats
MP3 for compatibility, M4A for Apple devices, WAV and FLAC for editing, OGG and Opus for small files.
Bitrate choice
From 320 kbps for music down to 64 kbps for voice notes.
Stays on your device
The audio is extracted in your browser. The video is never uploaded.
Frequently asked questions
What happens to 5.1 surround sound?
It is mixed down to stereo, since MP3 is a stereo format. Choose FLAC or WAV if you need to keep every channel.
My MKV has several audio languages. Which is extracted?
The default track is extracted. Video Info lists every track so you can check which one that is.
Which format gives the best quality?
M4A, when the video's audio is AAC, because it is copied without re-encoding. WAV and FLAC are also lossless copies of the decoded sound but larger. MP3 at 192 or 320 kbps is very close and plays everywhere.
Can choosing 320 kbps improve the original sound?
No. Re-encoding can only keep or lose detail, never add it. If the video's audio is 128 kbps AAC, a higher MP3 bitrate just makes a larger file.
Is my video uploaded?
No. The audio is extracted by FFmpeg running inside your browser.
Can I extract only part of the audio?
Extract the whole track here, then cut it with Audio Cutter, which also adds fades.
What if the video has no sound?
You will see a message that no audio stream was found, instead of an empty file.
Can I do this on my phone?
Yes, in Safari and Chrome. MP3 extraction from a long video takes a little longer on phones; M4A copy is instant.
Related tools
Audio Converter
Convert between MP3, WAV, M4A, OGG, FLAC and Opus, from audio or video.Audio Cutter
Cut a song or recording with fades. Save as MP3 or an iPhone ringtone.Remove Audio
Mute a video by removing its sound track, without re-encoding.Reduce Background Noise
Lower hiss, hum and steady background noise in a video or recording.Add Music to Video
Replace a video's sound or mix in music, with volume control and fade out.Change Video Volume
Make a quiet video louder, turn it down, or normalise loudness.Audio to Video
Turn a song, podcast or voice note into a video with a moving waveform.Fix Audio Delay
Shift the sound earlier or later to fix lip-sync, without re-encoding the picture.Guides
- How to Extract Audio from a VideoSave the sound from a video as MP3, M4A, WAV, FLAC or Opus: which format to pick, lossless copying, sensible bitrates and what to do afterwards.
- How to Make an iPhone RingtoneCut a song or a video's sound to 40 seconds or less, save it as an M4R ringtone, and add it to your iPhone with a Mac, a Windows PC or GarageBand on the phone.