Converters MP4 to MP3 converter
Pull the soundtrack out of an MP4 and save it as MP3, without the video ever leaving your device.
192 kbps is transparent for music. 128 is plenty for speech.
Drag files here, or
Converted to MP3 on your device. The converter itself is a 9.8 MB download, once.
Ready. Runs locally on your device.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
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Cite this page
Reembun. (2026, August 12). MP4 to MP3 converter. https://reembun.com/mp4-to-mp3
How to use it
Add the MP4
Drop the video in or choose it. The file stays on your device, which matters when it is a recording you cannot upload.
Wait for the engine once
The converter downloads on the first run and is cached afterwards, so the next extraction starts immediately.
Set the bitrate
MP3 is already the target. 128 kbps is plenty for a lecture or an interview, 192 kbps is the safer choice for music.
Download the audio
Only the soundtrack is written out, so the result is a fraction of the size of the video it came from.
Why extraction is fast even on a long video
An MP4 is a container holding two independent streams sitting side by side: a picture and a soundtrack. They are stored separately, not mixed together.
Extracting the audio means ignoring the video stream entirely and processing the other one. Nothing about the picture is decoded, so the resolution makes no difference at all. A two-hour 4K recording takes exactly as long as a two-hour 480p one, and both finish far faster than converting the video would.
The file gets dramatically smaller for the same reason. A 1 GB lecture recording typically becomes a 55 MB MP3, because the picture was almost all of it.
What people use this for
- Lectures and webinars. A two-hour recording becomes something you can listen to on a commute without burning mobile data.
- Transcription. Most speech-to-text services accept audio only and reject an MP4 outright.
- Interviews and meetings. The picture is rarely the part worth keeping.
- Music from a live recording, where the footage is shaky and the sound is not.
- Making a podcast episode out of a recorded video call.
MP3 or M4A?
The MP4 is almost certainly carrying AAC audio, which is the same codec an M4A file holds.
That gives you a choice most converters do not mention:
- To M4A, using the audio converter, the AAC stream is copied straight out with no re-encoding at all. The sound is bit-for-bit identical to the original and it is instant.
- To MP3, on this page, the audio is decoded and re-encoded. That costs a small amount of quality and buys universal compatibility.
Choose MP3 when the file has to play on a car stereo, a cheap player or transcription software. Choose M4A when you want the exact original sound and your destination accepts it.
Bitrate for spoken word
Most MP4s people extract audio from are somebody talking. For that, 128 kbps is enough and there is no argument to be had: a voice occupies a narrow frequency range and compresses extremely well. It sounds identical to 320 and takes 40% of the space.
| Content | Bitrate | 1 hour |
|---|---|---|
| Lecture, interview, webinar | 128 kbps | 57 MB |
| Podcast with music beds | 192 kbps | 86 MB |
| Live music recording | 320 kbps | 144 MB |
Nothing is uploaded
The MP4 files people extract audio from are recorded conversations: consultations, depositions, paid courses, internal meetings, calls under NDA. Handing those to an unknown server to save a couple of minutes is a poor trade.
This runs FFmpeg inside your browser tab. The video is read from your disk, and the soundtrack is written back to your downloads folder. Nothing is transmitted for the whole operation, because there is no server in the picture.
Common questions
How long does it take?
Seconds to a minute, even for a long recording. Extracting audio discards the video stream rather than processing it, so the work is proportional to the length of the soundtrack and not to the resolution of the picture. A two-hour 4K lecture is no slower than a two-hour 480p one.
Does the audio lose quality?
Slightly. An MP4 almost always carries AAC audio, and MP3 is a different codec, so the soundtrack is decoded and re-encoded. At 192 kbps and above that is inaudible to almost everyone. If you want the sound bit-for-bit unchanged, convert to M4A instead using the audio converter, which can copy the AAC stream across untouched.
What bitrate should I use?
128 kbps for anything that is talking, such as lectures, interviews, webinars and podcasts. It is indistinguishable on a voice and halves the file. Use 192 or 320 only when the MP4 contains music worth preserving.
Is there a file size limit?
Nothing imposed by us, because there is no upload. The practical ceiling is about 2 GB, which is where the 32-bit engine runs out of address space inside the browser tab. That covers a multi-hour recording comfortably.
The tool says there is no audio track. What now?
The video genuinely has no sound in it. Screen recordings made without selecting a microphone, and clips exported as video-only from an editor, contain a picture and nothing else. Play the MP4 with the volume up to confirm. If it is silent there, no converter can extract anything.
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