Convert MP4 to MP3
An MP4 holds its picture and its sound as separate tracks. This leaves the picture out and writes the sound as an MP3, the format nearly every phone, computer, car stereo and editor plays.
Your file never leaves this device. Everything runs in your browser.
How it works
- Drop your video.
- Pick MP3, WAV or M4A. The tool says whether the sound is copied or re-encoded.
- Press Extract and download the sound file.
Questions
What bitrate is the MP3?
192 kbps, constant, which takes about 1.4 MB a minute. MP3 rates run from 128 kbps for small files up to 320 kbps; 192 sits between the two, with room for music as well as speech.
Why is the sound re-encoded?
An MP4's sound is almost always AAC, not MP3, so it has to be decoded and encoded again as MP3. If you only need the sound on its own and not MP3 in particular, pick M4A: AAC sound is copied into it with nothing re-encoded.
Which format should I pick?
MP3 plays on almost anything. WAV is uncompressed, the format editors and DAWs take without converting. M4A is AAC sound in an MP4 container: it's what most phones and cameras record, so it's usually copied rather than re-encoded.
Does extracting lose quality?
Not when the sound is copied into an M4A, and not in a WAV, which stores the decoded sound uncompressed. An MP3, or an M4A made from sound that isn't AAC, is re-encoded at 192 kbps, which keeps music and speech clear but, like any re-encode, isn't bit-for-bit the original.
Is there a length limit?
Files up to 2 GB, and no limit on length: sound is quick to encode. A WAV gets large, though: about 11.5 MB a minute for 48 kHz stereo.
Can I keep only part of the sound?
Trim the video first with Trim a video. Its fast mode cuts without re-encoding. Then drop the trimmed file here.
Does my video get uploaded?
No. The sound is read and written in your browser, on your device.
Which browsers does it work in?
Current Chrome, Edge, Safari and Firefox. Browsers have no MP3 encoder of their own, so the page loads LAME, the open-source MP3 encoder, compiled to WebAssembly (about 300 KB, from this site) the first time you make an MP3. If your browser can't read the sound in your file, the tool says so before it starts.