Convert MKV to MP3 online

If you have a movie, a show, or an anime episode saved in MKV and only want to keep the sound — the dialogue, the soundtrack, or a specific song — this converter extracts the audio and saves it as MP3 right in your browser, without uploading the file to any server.

What's extracting the audio from an MKV good for?

MKV is the go-to container for movie, show and anime rips because it can hold high-quality video alongside multiple audio and subtitle tracks in a single file. A lot of the time, all you actually need is the sound: listening to a filmed audiobook, keeping the soundtrack of a scene, or simply because the full video file is too heavy for what you want to do with it. Extracting the audio to MP3 gets you exactly that, without carrying the video along.

How it works: converted in your browser, not on a server

We use ffmpeg compiled to WebAssembly, running inside your browser tab. When you hit 'Convert', the default audio track gets pulled out of the MKV file and encoded as MP3 with libmp3lame, without the video ever leaving your machine. The result downloads directly, just like any other file.

Steps to extract the audio from your MKV

• Choose the MKV file from your device ('Choose file' button).
• Hit 'Convert'. The first time, your browser downloads the conversion engine (a few MB); after that, it's faster.
• Wait for the progress bar to reach 100%.
• Download the resulting MP3 with the 'Download result' button.

Which audio track gets extracted

An MKV can carry several audio tracks — different languages or commentary tracks, for instance. This converter pulls out whichever track is flagged as default in the file, which usually matches the main language or mix. If your MKV has multiple tracks and you need a specific one that isn't the default, you'll need desktop software that lets you select it before extracting.

Honest limits worth knowing

Since the conversion happens in your browser, the real limit is your device's memory when loading the file, not an artificial cap of ours. Movie-rip MKVs can weigh several GB; loading them can take longer on phones with limited RAM, though extracting just the audio is lighter than converting the whole video. This converter processes one file at a time, on a single thread.

Other related conversions

If instead you need the full video in a more compatible container, use MKV to MP4 (instant remux, no re-encoding). And if your file is already in MP4, extract the audio directly with MP4 to MP3. If you don't have the file yet, use our YouTube video downloader.