How to convert MKV to MP3
Drop your MKV files into the box above, or click Choose files. You can add several at once.
Pick a bitrate. 192 kbps sounds transparent to most listeners; 320 kbps is the maximum.
Click Convert to MP3. Files are processed on your device; a few minutes of media usually takes seconds.
Download the MP3 files one by one, or all at once as a ZIP.
Why convert MKV to MP3?
OBS Studio and many other recorders save MKV files, because a recording survives a crash. When you only need the sound, like a podcast, a stream's commentary or a recorded talk, an MP3 is far smaller and plays everywhere.
MKV files are often huge. Extracting the audio on your device avoids uploading gigabytes to an online converter.
Recordings stay private: they never leave your computer.
MKV vs MP3
MKV (Matroska) is a flexible container that can hold almost any video and audio codec, often with several audio and subtitle tracks. MP3 holds a single audio track and plays on any device.
The main audio track is decoded and re-encoded as MP3 at the bitrate you choose. The video and any other tracks are discarded.
| Property | MKV | MP3 |
|---|---|---|
| File size | Depends on the codecs inside | About 1 MB per minute at 128 kbps |
| Best for | Archiving films with multiple audio and subtitle tracks | Music and podcasts on any device |
| Support | VLC and desktop players; not iPhones or most browsers | Every player, phone, car and browser |
Is it safe?
Yes. MKV to MP3 runs entirely in your browser. Your files are read and converted by your own device using built-in browser technology, so they are never uploaded to a server and nobody else can see them.
You can check this yourself: open your browser's developer tools, switch to the Network tab and convert a file. No upload requests are made.
Audio is decoded and encoded by your browser, using its built-in media engine and a WebAssembly MP3 encoder. Recordings, voice memos and interviews never leave your device.
Files stay in this tab's memory only until you remove them or close the page.
Frequently Asked Questions
My MKV has several audio tracks. Which one is used?
The file's main audio track, usually the first one. Other tracks and subtitles are ignored.
Why won't some films convert?
Films often carry Dolby Digital (AC-3) or DTS surround sound, which most browsers can't decode. Recordings from OBS and similar tools use AAC or Opus, which work everywhere.
Do I need to remux an OBS recording to MP4 first?
No. OBS can remux MKV to MP4, but you don't need to: the audio is read straight from the MKV and saved as MP3.
Which bitrate should I choose?
192 kbps is the default and sounds transparent to most listeners. 128 kbps is fine for speech and halves the size; 320 kbps is the maximum MP3 quality.
Is there a file size limit?
Each file can be up to 500 MB. Files are read from disk in small pieces, so long recordings don't need to fit in memory.