MKV to MP3 Converter
A free MKV to MP3 converter that works in the page: drop the .mkv, keep MP3 or switch to WAV, and download the sound track on its own. The video is converted on your computer and is not uploaded. Use Chrome, Edge or Firefox; Safari reads only some MKV files, as explained below.
Drop your MKV here or click to browse
MKV (and other video files) up to 500 MB and 30 minutes. Works best in Chrome, Edge or Firefox.
The video is converted in your browser and is not uploaded.
How to convert MKV to MP3
Three steps, no install and no account.
- 1
Open this page in Chrome, Edge or Firefox
Chrome and Firefox read the sound in MKV files. Safari reads it only when the sound is Opus, so on a Mac or iPhone, Chrome, Edge or Firefox on a computer is the sure route.
- 2
Drop the MKV and pick the output
Drag the .mkv onto the converter or click to choose it. MP3 is already selected at 128 kbps; pick 64 or 96 for a voice recording, 192 or 320 for music, or switch to WAV.
- 3
Extract, listen, download
Press Extract audio, play the preview and download. The MP3 keeps the video's name with an .mp3 ending. Up to 500 MB and 30 minutes per file.
What is inside an MKV file
MKV is the file ending of Matroska, an open container format. Knowing what a container holds explains most MKV surprises.
A container, not a codec
Matroska describes itself as an envelope, not a compression format. The picture and the sound inside are encoded with separate codecs, and whether a browser can read the sound depends on that codec, not on the .mkv ending.
Several sound tracks
One MKV can carry many audio streams, for example two languages or a commentary track. The converter takes the first audio track in the file, which is what the Web Audio standard tells browsers to decode.
Subtitles and chapters stay behind
MKV files can also hold subtitle streams and chapter entries. An MP3 is sound only, so subtitles, chapters and the picture are left out; the sound track is what you get.
WebM is Matroska's web cousin
MDN describes WebM as a format based on Matroska, made for the web. A .webm file converts on this page too, in Chrome, Firefox and Safari alike.
Which MKV files convert, and where
The converter uses the browser's own audio decoder, so the browser decides what it can read. In the parent converter's test of 30 September 2026 (Chrome 154, Firefox 156, Safari 26.6), Chrome and Firefox read the sound in MKV files, and Safari read it only when the sound track was Opus. When Safari cannot read a file, the converter tells you: "Safari cannot read this MKV file's sound track. Open this page in Chrome, Edge or Firefox, or export the video as MP4." Every browser on iPhone and iPad uses Safari's engine, so the same applies there.
The sound codec matters in every browser. The converter's error message names Dolby AC-3 in Chrome or Firefox as a codec those two browsers cannot decode; in the same test an MP4 with AC-3 sound decoded only in Safari. If an MKV will not convert in Chrome or Firefox, check whether its sound track is Dolby (AC-3).
When the file has several sound tracks, the Web Audio API standard says the browser decodes only the first one. The converter has no track picker, so if the first track is the wrong language or a commentary, make a copy of the MKV that keeps only the track you want (MKVToolNix's mkvmerge does this with its --audio-tracks option) and convert the copy.
When the sound will not come out
Three causes cover almost every failed MKV.
You are in Safari or on an iPhone
Open the page in Chrome, Edge or Firefox on a computer and drop the same file again. Safari reads MKV only with Opus sound.
The sound is Dolby AC-3, or there is none
Chrome and Firefox cannot decode AC-3. Export the video again as MP4 with AAC sound, or try the file in another browser. A screen recording made without the microphone has no sound track to extract.
You got the wrong track
The browser decodes the first audio track. Save a copy that keeps only the track you want, then convert that copy.
How big the MP3 gets
An MP3's size depends only on its length and bitrate, not on the video's resolution, so a 1080p MKV and a 480p one of the same talk give the same MP3. The converter shows the estimate for your file before you convert.
| Output | 1 minute | 10 minutes | 30 minutes |
|---|---|---|---|
| MP3 64 kbps | 469 KB | 4.6 MB | 13.7 MB |
| MP3 96 kbps | 703 KB | 6.9 MB | 20.6 MB |
| MP3 128 kbps | 938 KB | 9.2 MB | 27.5 MB |
| MP3 192 kbps | 1.4 MB | 13.7 MB | 41.2 MB |
| MP3 320 kbps | 2.3 MB | 22.9 MB | 68.7 MB |
| WAV 44.1 kHz stereo | 10.1 MB | 100.9 MB | 302.8 MB |
| WAV 16 kHz mono | 1.8 MB | 18.3 MB | 54.9 MB |
Sources
Transcribing a recorded interview or group session? Read: how to transcribe an interview, focus group transcription, user research interviews, oral history transcription.
Next time, record the sound and skip the conversion
Pulling the audio out of a video is a step after the fact. ParrotNotes records the meeting, call or interview on your phone and gives you the transcript and a summary, free for 100 minutes of recording a month. For the MP3 you just made, the free Audio to Text Converter transcribes files up to 10 minutes.
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