MP4 to MP3
Drops the video, keeps the soundtrack, and re-encodes it as an MP3 in your browser.
Drop an MP4 here
Everything happens on your device — your files are never uploaded.
file.mp4
Converting…
Done
What this does
This pulls the audio track out of an MP4 and writes it to a standalone MP3. The video frames are discarded; only the sound is kept, then re-encoded to MP3 in your browser.
MP3 is a lossy format, so the audio is compressed again from the source track. The result is smaller than the original video and sounds close to it, but it isn't a bit-perfect copy. Tags like title or artist from the MP4 aren't carried over — the output is plain audio.
How it works
- 1 Drop your MP4 or pick it from your device.
- 2 Click Convert to MP3. The audio track gets pulled out right in your browser.
- 3 Download the MP3 when it's ready.
Built with open source
- Mediabunny — Converts and edits video and audio in the browser via WebCodecs. Add-on encoders cover MP3, AAC, and FLAC. · MPL-2.0
Frequently asked
Does my video get uploaded anywhere? +
No. The whole conversion runs in your browser. The MP4 stays on your device and nothing goes to a server. There's no sign-up and no watermark.
Why does the first conversion pause for a moment? +
Browsers can't encode MP3 on their own, so the first run fetches a small (~300KB) MP3 encoder. After that it's cached and conversions start right away.
Is the audio quality reduced? +
MP3 is a lossy format, so the audio gets re-encoded. It stays close to the source. Want a perfect copy? Use the MP4 to WAV tool instead.
Is there a file-size limit? +
There's no fixed cap. The video is decoded in memory as it converts, so the practical limit is your device's RAM. Very long or large files will use more memory and take longer.
Can I convert other video formats? +
The picker also accepts MOV, M4V, WebM, MKV, and AVI. As long as the browser can decode the audio track inside the file, it converts the same way.
What happens to the video and any subtitles? +
Both are dropped. Only the audio track is read; video frames, subtitle tracks, and chapter data don't make it into the MP3.
If the video has several audio tracks, which one is used? +
The primary audio track is extracted to a single MP3. The tool doesn't split out alternate-language or commentary tracks separately.
Does it work offline and on any browser? +
It runs in any modern browser on desktop or mobile. Once the page and the MP3 encoder are cached, conversions work without a connection.