MKV to MP3 Converter
Convert MKV to MP3 to keep the soundtrack of a concert recording, a lecture or a music video as a plain audio file. ProMedia reads the Matroska file’s main audio track, whether it is AAC, Opus, FLAC, AC-3 or DTS, and saves it as an MP3 at up to 320 kbps. Audio-only .mka files work too. Everything happens in your browser, with no upload and no size cap.
- Runs on your device
- WebCodecs · GPU
- FFmpeg
- Works offline
Updated
Drop your videos here
How to convert MKV to MP3
Step 1: Drop your MKV (or MKA) files on the box above.
Step 2: Pick a Bitrate. 192 kbps suits most films and music; 320 kbps is the MP3 maximum.
Step 3: Press Convert. AC-3 and DTS tracks load the FFmpeg engine once (about 31 MB).
Step 4: Download the MP3 files, or all of them as one ZIP.
Good to know
Settings explained
- Bitrate
- 192 kbps suits most films and music; 320 kbps is the MP3 maximum.
Formats
Batch-friendly: add many files and they are processed one after another — if one fails, the rest still finish.
How it runs
- Hardware video engine
- Video is decoded and encoded by your device’s media hardware through WebCodecs — usually several times faster than real time.
- FFmpeg (when needed)
- Older formats and a few filters use FFmpeg compiled to WebAssembly. It downloads once (about 31 MB) the first time it is needed and is cached for offline use.
What audio is inside an MKV, and what happens to it
MKV can carry almost any audio codec, which is why the same “MKV to MP3” job can be quick or need an extra engine. Every codec below ends up as MP3; the table shows where each one usually comes from and how it is decoded.
| Audio in the MKV | Common source | How it is decoded |
|---|---|---|
| AAC | Web downloads, phone and screen recordings | In the browser |
| Opus or Vorbis | Web video and some recorders | In the browser |
| FLAC | Concert and music rips | In the browser |
| AC-3 or E-AC-3 (Dolby Digital) | TV recordings, DVD and Blu-ray rips | FFmpeg engine in browsers without a decoder |
| DTS | Blu-ray rips | FFmpeg engine |
| MP3 | Older rips | Decoded and re-encoded at your bitrate |
What is an MKV file?
An MKV file is a Matroska container: an open format that can hold video, several audio tracks, subtitles, chapters and attached fonts in a single file. Film and series rips, concert recordings and OBS captures often use it. An MKA file is the same container with audio only.
Which audio track is converted?
The MKV’s main audio track, the one marked as default or listed first, is converted. Many films carry several tracks, such as different languages or a commentary; ProMedia does not offer a choice of track yet, so the others are skipped. If you need a different language, play the file in a player that lists the tracks to see which one is the default.
Does MKV to MP3 lose quality?
Some, because MP3 is a lossy format and every source is decoded and compressed again. From FLAC or other lossless audio, 320 kbps MP3 is very close to the original. From AC-3 or DTS surround, the result is a stereo MP3 that keeps the dialogue and music but not the separate surround channels. For a lossless copy, save FLAC or WAV with extract audio from video instead.
Why use this MKV audio extractor
- Handles the hard codecs. AC-3 and DTS, which many browsers and phones cannot play, are decoded by the built-in FFmpeg engine.
- No upload of large rips. A multi-gigabyte film is read from your disk; only the audio is written out.
- Batch a whole season. Drop every episode or every concert file at once and download the MP3s as one ZIP.
- Offline once loaded. After the first visit, and the one-time engine download, it works without a connection.
Tips & troubleshooting
Want the video too, as a phone-friendly file? MKV to MP4 copies the picture losslessly and converts DTS or AC-3 to AAC.
Film dialogue too quiet next to the music? Run the MP3 through normalize audio.
Need only one song from a concert? Cut it from the MP3 with the MP3 cutter.
Subtitles wanted as well? Save them first with Extract Subtitles.
MKV to MP3 Converter FAQ
How do I extract audio from an MKV file?
Drop the MKV on this page, pick a bitrate and press Convert; you get an MP3 of the main audio track. For other formats such as FLAC, WAV or M4A, use the extract audio from video tool, which reads MKV in the same way.
Can MKV audio be DTS or AC-3?
Yes, and it often is in film and TV rips. Both are decoded on your device: in the browser where it has a decoder, otherwise by the FFmpeg engine, which downloads once. The surround channels are mixed down to stereo for the MP3.
Does MKV to MP3 lose quality?
A little, as with any MP3. At 192 to 320 kbps it is hard to hear on music and speech. Lossless sources such as FLAC keep the most detail; surround sources lose their separate channels because MP3 is stereo.
Can I choose which audio track to convert?
Not yet. The default (main) track is converted and other language or commentary tracks are skipped. A desktop player that lists the tracks will show you which one is the default before you convert.
Does it work with MKA files?
Yes. An MKA file is a Matroska container with audio only, and it converts to MP3 exactly like an MKV.
Is your file uploaded anywhere?
No. Your file is processed by your own browser on your own device. There is no server that receives files, so nothing is uploaded, stored or shared. You can even switch to airplane mode once the page has loaded.