MKV to MP3 Converter
Convert MKV to MP3 free — no upload, no signup
To convert MKV to MP3, drop your MKV video into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. Extract MP3 audio from MKV files, whatever codec they use.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
Advanced
How to convert MKV to MP3
Add your MKV videos
Drag and drop MKV files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Pick a bitrate
192 kbps suits music and 128 kbps or less suits speech. Sample rate and mono/stereo are under Advanced.
Convert and download
Click Convert, then download each MP3 file or all of them as one ZIP.
Why convert MKV to MP3?
MKV movies, OBS recordings and anime episodes often carry Opus, AC-3, DTS or FLAC audio that some players can't handle. MP3 plays everywhere.
What happens when you convert MKV to MP3?
Fylo decodes the first audio track — Opus, Vorbis, AAC, AC-3, FLAC and more — and encodes MP3. Other audio tracks and subtitles are ignored.
How does Fylo convert MKV to MP3?
Fylo decodes the soundtrack of the MKV (usually Any: AAC) with ffmpeg compiled to WebAssembly and encodes it with the LAME MP3 encoder at 192 kbps (adjustable from 96 to 320 kbps). The video stream is skipped entirely, which is why extraction is fast — the MP3 is a fraction of the video's size. The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between MKV and MP3?
MKV is the Matroska container, an open standard first released in 2002. It can hold virtually any video, audio or subtitle codec, and any number of tracks — so one file can carry several languages, director's commentary and subtitles. WebM is a restricted subset of Matroska.
MP3 (MPEG-1 Audio Layer III) was developed largely at Germany's Fraunhofer Institute and standardised in 1993. It removes sounds the ear is unlikely to notice — a technique called perceptual coding — so a 3-minute song takes about 4 MB at 192 kbps instead of about 32 MB as WAV. The last MP3 patents expired in 2017, so it's now free to use.
Learn more: MKV format guide · MP3 format guide
| Property | MKV | MP3 |
|---|---|---|
| Type | Video | Audio |
| Contains | Video (Any: H.264, HEVC, VP9, AV1…) + audio (Any: AAC, Opus, FLAC, DTS, AC-3…) | Audio only, lossy |
| Developed by | Matroska project (open standard) | Fraunhofer IIS / MPEG |
| Introduced | 2002 | 1993 |
| Compatibility | VLC, Plex, Kodi, most smart TVs; not iPhone or many editors | Universal |
| Best for | Movies with multiple audio and subtitle tracks | Music and podcasts on any device |
Frequently asked questions
Which audio track is used?
The first audio track in the MKV.
Is surround sound kept?
The MP3 is stereo; surround tracks are mixed down.
Is my MKV file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your MKV file is read directly from your device and never sent anywhere.
Related tools
Updated