Audio conversion uses FFmpeg through the single-threaded @ffmpeg/core 0.12.10 build, licensed under GPL-2.0-or-later. FFmpeg. ffmpeg.wasm.
MKV files are flexible. One file can carry video, several audio tracks, subtitles and chapters. That flexibility also makes them awkward: many phones, cars and editors cannot open them. This free MKV to MP3 converter takes the soundtrack and gives you a plain MP3. The video stays on your computer. For other video types, use the video to MP3 converter.
How do I convert MKV to MP3?
- Click Browse files or drag the .mkv file onto the converter.
- Choose the Audio quality: 192 kbps for most soundtracks.
- Click Convert to MP3.
- Click Download MP3.
What is an MKV file?
MKV is the video file of Matroska, an open-source multimedia container first released in 2002. It is not a codec: it can hold almost any video and audio codec, such as H.264, HEVC or AV1 video with AAC, AC-3, DTS, FLAC, Opus or Vorbis audio. The WebM format is a restricted version of Matroska.
Because the audio inside an MKV varies so much, so does the right bitrate:
| Audio track in the MKV | Suggested MP3 bitrate |
|---|---|
| FLAC or PCM (lossless) | 320 kbps |
| AC-3, DTS or high-bitrate AAC (film soundtracks) | 256 or 320 kbps |
| Opus, Vorbis or AAC at normal bitrates | 192 kbps |
| Speech, lectures, recordings of calls | 128 kbps |
Surround soundtracks (5.1 and up) become a stereo MP3, the layout MP3 players expect.
Which audio track does the MKV converter use?
The first one in the file. We tested MKV files with two audio tracks, and the MP3 contained the first track. That is normally the main language or the original mix.
If you need a different track, such as a second language or a commentary, use a desktop tool:
- MKVToolNix: load the MKV, untick every audio track except the one you want, and save a new MKV. Then convert that file here.
- FFmpeg: run ffmpeg -i input.mkv -map 0:a:1 -c:a libmp3lame -b:a 192k output.mp3, where 0:a:1 means the second audio track.
How long can my MKV be?
The page accepts MKV files up to 150 MB. MKVs are often big because they hold high-resolution video and several tracks, so 150 MB may be only a few minutes of a 1080p film. Cut a shorter section with MKVToolNix or your video editor, then convert that.
Limits of the MKV to MP3 page
It only accepts .mkv files, one at a time, up to 150 MB. It converts the first audio track only, does not keep subtitles or chapters, and does not download videos from links. For other files, use the main MP3 converter.
Frequently asked questions about MKV to MP3
Is this MKV to MP3 converter free?
Yes. It is free with no sign-up, and the conversion runs in your browser.
Is my MKV video uploaded?
No. The file stays on your device; the MP3 is created in the browser.
My MKV has two languages. Which one do I get?
The first audio track in the file. To pick another, use MKVToolNix or FFmpeg as described on this page.
Does a 5.1 surround track work?
Yes. It is converted to a stereo MP3.
Can VLC convert MKV to MP3?
Yes. VLC has a Convert / Save option with an MP3 audio profile. This page is quicker when you only need the first track and do not want to install anything.
Why is my MKV larger than 150 MB?
High-resolution video makes MKVs large. Trim the part you need first, then convert it.
Convert your MKV to MP3
Choose the MKV, select the quality and download the soundtrack as MP3.
Other video to MP3 converters
- WEBM to MP3: browser and screen recordings.
- MP4 to MP3: the most common video format.
- MOV to MP3: iPhone and QuickTime videos.
- Video to MP3 converter: every video format in one place.