CFN

MP4 to MP3 Converter — Free Online, Extract Audio

Extract the MP3 audio track from any MP4 video file free online. Fast, in-browser, no upload, no signup.

How to extract MP3 from a video

Step 01

Drop a video file. The first time, the FFmpeg engine downloads (~30 MB).

Step 02

Pick the desired audio bitrate. 192 kbps is a good default.

Step 03

Click Extract. The audio is encoded in your browser.

Download the resulting MP3 file.

Extract the audio track from an MP4 video as a standalone MP3 file, locally and privately. Like every tool on this site, the mp4 to mp3 converter — free online, extract audio runs entirely inside your browser. Your files are never uploaded to a server. There are no accounts, no monthly limits, and no watermarks — just an honest tool that does one job well.

Common use cases

Listening to a lecture, podcast interview, or talk that was originally published as a video, in a player that does not need the visual stream.

Saving the soundtrack of a music video for offline listening on a phone, smart speaker, or car system that prefers MP3 over MP4.

Transcribing a meeting recording — many transcription tools accept audio-only inputs and run faster on MP3 than on MP4.

How it works

Drop in your MP4. FFmpeg WebAssembly opens the container, identifies the audio track, and reads its samples — without ever uploading the file.

Choose your output bitrate. 128 kbps is good for spoken word, 192–320 kbps is a safer choice for music. Higher bitrates produce larger files but better fidelity.

The encoder writes a standard MP3 file to your downloads. The original MP4 stays on your device, untouched.

Privacy by design

We built this tool to demonstrate that powerful file utilities do not require sending your data to a remote server. Every byte stays on your device.

Hosting and bandwidth aren't free, so the site is supported by privacy-respecting display advertising. Ads never have access to your files because the ads run in a separate iframe and the files never leave your browser memory in the first place.

You can opt out of personalised advertising at any time via the cookie banner at the bottom of the page. Functional behaviour of the tools does not change based on your consent — it only affects the type of ads displayed.

Frequently asked questions

Is it really free?

Yes. There are no fees, no monthly limits, and no premium tier. The tools are funded by display advertising.

Are my files private?

Completely. Everything runs in your browser. We don't have a server that sees your files.

Will it work on my phone?

Yes. Every tool is responsive and works on iOS Safari and Android Chrome. Some heavy operations (large videos, complex PDFs) may be slow on older devices because the work happens locally rather than on a server.

Do I need an account?

No. Tools work immediately, with no signup or login.

Can I use it for commercial work?

Yes. There are no restrictions on the type of file you process or what you do with the result, beyond not violating the law or our Terms of Service.

Where can I report a bug or request a feature?

The Contact page lists an email address — we read every message and try to respond within a couple of business days.

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