How do I convert MP4 to MP3?

Leave From on MP4 and To on MP3, press Open audio or drop the video on the stage, choose a bitrate, press Convert and then Download. A video with more than one audio track asks which one first. The MP3 keeps the video's name with the new extension.

Can this convert a video without uploading it?

Yes. The MP4 is read and decoded in your browser, and only its audio track is encoded. No file bytes leave this device.

What if the MP4 has multiple audio tracks?

The page lists the available tracks with their codecs and channels so you can choose one before converting.

Does it work with MOV or WebM videos, or on a phone?

Yes. A MOV or WebM opens in the same MP4 mode, because only its audio track is taken. It runs in a current browser on an iPhone, Android phone, Mac, Windows PC or Chromebook with nothing to install, and on an iPhone the MP3 goes to the Downloads folder in the Files app by default.

MP4 to MP3 Converter

Choose an MP4 with an audio track and this page extracts that soundtrack locally, then encodes it as an MP3. A MOV from a phone or a WebM from a screen recorder opens the same way. The video stays untouched, and the file is never uploaded.

Open an MP4, MOV or WebM file

· or drop one anywhere on the stage

Never uploadedNo accountUp to 50 MBUp to 10 minutes

From · opens MP4, MOV or WebM

Bitrate

Sample rate

Channels

Download

Ready. Choose an MP4, MOV or WebM file, or drop one on the stage.

Audio tracks are listed before extraction, the video is never decoded, and a file with no audio track is refused. A MOV or WebM video opens here too. The output is a constant bitrate MP3 at the bitrate you choose, which is a lossy encode of what came in.

What the bytes sayread from the first bytes of the file, never from its extension
Open a file and its container is identified before anything is decoded.
Output sizeexact arithmetic for PCM, an estimate for MP3
Open a file to size the output.
Decoderasked of this browser before a conversion starts
A codec with no decoder here is named up front, not halfway through.

The From control is a mode, not a guess: the first bytes of the file are read and checked against it, so a file that was renamed is refused with what it actually is. A bare AAC opens in M4A mode, and a FLAC in WAV mode. Changing the sample rate resamples by linear interpolation, and changing the channel count averages a stereo pair down or copies a mono channel to both sides.

Two open source parts do the heavy lifting. Containers are parsed and audio is decoded by Mediabunny 1.55.7 under the MPL-2.0 (licence text, the exact package, source). MP3 encoding is lamejs 1.2.7 under the LGPL-3.0 (licence text, the exact package, corresponding source). Both are bundled unmodified at those versions and loaded from this page, never from another service.

Common questions

How do I convert MP4 to MP3?: Leave From on MP4 and To on MP3, press Open audio or drop the video on the stage, choose a bitrate, press Convert and then Download. A video with more than one audio track asks which one first. The MP3 keeps the video's name with the new extension.
Can this convert a video without uploading it?: Yes. The MP4 is read and decoded in your browser, and only its audio track is encoded. No file bytes leave this device.
What if the MP4 has multiple audio tracks?: The page lists the available tracks with their codecs and channels so you can choose one before converting.
Does it work with MOV or WebM videos, or on a phone?: Yes. A MOV or WebM opens in the same MP4 mode, because only its audio track is taken. It runs in a current browser on an iPhone, Android phone, Mac, Windows PC or Chromebook with nothing to install, and on an iPhone the MP3 goes to the Downloads folder in the Files app by default.

Files are decoded and re-encoded in your browser, so nothing is uploaded. Converting cannot restore detail a lossy file already lost, and an MP3 output is a lossy encode of its own. Which formats can be decoded depends on your browser, and this page checks the file's actual bytes and its codec before starting rather than trusting the extension.