MKV to MP3 Converter

Converting MKV to MP3

1. Open the MKV with the box above. The file card shows which audio codec it contains.
2. Pick an MP3 quality: 192 kbps by default, 320 kbps for music, 128 kbps for voice.
3. Convert, check the result in the player, and download.

Why MKV files need converting

Matroska (MKV) is a flexible open container. It can hold almost any video and audio codec, multiple audio tracks and subtitles, which is why OBS users, archivists and film rippers like it. The flexibility is also the problem: phones, car stereos and many apps can't play MKV at all. An MP3 of the soundtrack plays everywhere.

Surround sound and multiple tracks

Films in MKV often carry AC-3 (Dolby Digital) 5.1 sound. MP3 is stereo, so the converter downmixes the surround channels to two; dialogue from the centre channel ends up in both speakers. This was tested with AC-3 tracks, and Opus, AAC and Vorbis tracks convert the same way.

When an MKV holds several audio tracks, such as different languages or a commentary, the converter uses the first one. OBS users who record game sound and microphone on separate tracks get the first track, which is normally the combined mix.

Recordings from OBS

OBS Studio can record to MKV, a popular choice because a crash or power cut doesn't corrupt the whole file the way it can with a plain MP4. Converting a stream recording or a podcast session to MP3 here takes seconds to minutes depending on length, and you never need to remux the MKV first.

When you want text rather than sound

For a transcript or subtitles of an MKV recording, mydubly reads the MKV directly on the MKV to text page. The MKV vs MP4 article explains when each container is the better choice for your recordings.

How the free converter works

The converter is ffmpeg, the open-source media toolkit, compiled to WebAssembly so it runs inside your browser tab. Your file is read straight from your disk by that engine; it is never uploaded to mydubly or anywhere else, and no account is needed.

• The engine is about 30 MB and downloads the first time you convert something. After that your browser normally keeps it.
• Large inputs are fine because the file is read in place, but the result is built in memory, so outputs are capped at about 1.5 GB.
• Speed depends on your device. Copying streams takes seconds; re-encoding video is the slow case.
• Keep the tab open until the download button appears. Closing it stops the conversion.