How to get the audio from a video (MP4 to MP3)
To get the audio from a video, save its sound track as a file of its own, as MP3 to play everywhere, or as M4A to keep the video's AAC sound exactly as it is. On tuul.io/mp4-to-mp3/ you drop the video, pick 192 kbps (the standard) or 320 kbps for music, and download the MP3. It runs in your browser, so the video isn't uploaded. On a Mac, QuickTime Player's File > Export As > Audio Only saves an M4A without any extra app.
What you’re actually doing
A video file holds a picture track and, usually, a sound track side by side. Getting the audio means copying the sound track into a file of its own and leaving the picture behind. Nothing is “ripped” out of the picture; the sound was always a separate stream.
In most MP4 and MOV videos, from phones, cameras and screen recorders, that sound is AAC. That’s where the choice between MP3 and M4A comes from.
MP3 or M4A?
| MP3 | M4A | |
|---|---|---|
| What it is | The classic audio format | AAC sound in an audio-only MP4 file |
| Plays on | Everything: phones, computers, car stereos, old MP3 players | iPhone, Mac, Android, Windows and browsers; not some older devices |
| Quality | Re-encoded from the video’s sound; at 192 kbps it sounds the same to most people | Identical to the video, because the sound is copied, not re-encoded |
| Speed | Takes longer, because the sound is encoded | Fast, because the sound is only copied |
| Choose it when | It must play anywhere, or a form or app asks for MP3 | You want the original sound, for editing or archiving |
MP3’s patents have expired, so every device and app can play it without a licence. MDN’s codec guide notes AAC was designed to give “more compression with higher audio fidelity than MP3”, which is why video uses it. An M4A copy is often smaller than an MP3 of the same sound, and it’s exactly what you heard in the video.
M4A only works when the video’s sound is AAC. Films in MKV often have Dolby (AC-3) sound, and CCTV cameras record G.711. For those, choose MP3.
Which MP3 bitrate?
The bitrate is how much data each second of sound gets. It sets both quality and size:
| Bitrate | Size per minute | Good for |
|---|---|---|
| 128 kbps | about 0.96 MB | Speech, lectures, voice notes, camera sound |
| 192 kbps | about 1.44 MB | Most music and video sound; the standard |
| 256 kbps | about 1.92 MB | Music, a little extra headroom |
| 320 kbps | about 2.4 MB | The most MP3 can hold; music you care about |
To work it out yourself: kbps × seconds ÷ 8 = kilobytes. An hour-long lecture at 128 kbps is about 58 MB; at 320 kbps, 144 MB. MDN suggests “at least 192 kbps if possible” for music.
One thing a bitrate can’t do is add quality. The MP3 can only be as good as the sound in the video. A phone video with modest AAC sound gains nothing at 320 kbps, and a security camera that records at telephone quality (8 kHz) sounds the same at 128 kbps.
Get the audio in your browser
This works the same on Windows, Mac, Chromebooks, iPhone and Android, with nothing installed.
- Open tuul.io/mp4-to-mp3 for MP4 videos, tuul.io/mov-to-mp3 for iPhone and Mac videos, or tuul.io/video-to-mp3 for MKV, WebM, AVI and CCTV recordings. Each page accepts all of these; only the file picker differs.
- Drag your videos onto the page, or tap Choose files and pick them. Several at once is fine.
- Under Save as, keep MP3 and pick a quality (192 kbps is the default), or choose M4A to copy the AAC sound without re-encoding.
- Listen to each result on the page, then download it, or press Download all to get every file in one ZIP.
The converter downloads once to your browser and then works on your device, so the videos never leave it. A few details it handles for you:
- Only the first sound track is saved. The picture, subtitles and any extra sound tracks are left out, and the row says when there were more.
- Surround sound is mixed down to stereo, because MP3 holds at most two channels.
- MP3 sound is copied, not re-encoded, when the video already has MP3 audio at or below the bitrate you chose.
- The location your phone stored in the video, and other metadata, isn’t copied into the audio file.
- A video with no sound gets a row that says so, and the rest of the batch carries on.
On a phone, very long videos need a lot of memory; for files over about 1 GB, a computer is more reliable. To keep only part of the sound, cut the video first on tuul.io/video-trimmer, which copies the part you keep without re-encoding, then convert the clip.
Built-in ways
- Mac: open the video in QuickTime Player and choose File > Export As > Audio Only. Apple describes the result as “an Apple MPEG 4 audio file with an AAC audio track”, an M4A. There’s no MP3 option.
- Windows: there’s no one-click option in Windows itself. The free VLC player can do it: Media > Convert / Save, add the video, choose Convert, pick the profile Audio - MP3, set a file name ending in .mp3 and press Start.
- iPhone and Android: the Photos and Gallery apps have no “save audio” button. A browser converter is the simplest way without installing an app.
A note on whose sound it is
Getting the sound from your own videos, a family recording or a lecture you’re allowed to keep is fine. Music and films from streaming services are protected by copyright, and their terms usually forbid saving them. tuul’s converters only work on files already on your device; they don’t download anything from YouTube or other sites.
Sources
- Apple Support: Export movies to other file formats using QuickTime Player on Mac: the Audio Only option.
- MDN: Web audio codec guide: MP3 and AAC, bitrates and MP3’s expired patents.
- University of Michigan ITS: Convert video to audio using VLC: the VLC steps.
- VideoLAN: VLC media player.
Questions
Does converting MP4 to MP3 lose quality?
A little, because MP3 is lossy and the sound is encoded again. At 192 kbps or more it sounds the same as the video for almost everyone. To keep the sound exactly as it was, choose M4A on tuul.io/mp4-to-mp3/, which copies the video's AAC sound without re-encoding it.
What bitrate should I choose for MP3?
192 kbps for most things, 320 kbps for music you care about, and 128 kbps for speech, lectures and voice notes. A higher bitrate can't add quality the video didn't have, so 320 kbps from a phone video with 128 kbps sound only makes a bigger file.
How do I get the audio from an iPhone video without an app?
Open tuul.io/mov-to-mp3/ in Safari on the iPhone, tap Choose files, pick the video from your photo library and download the MP3 or M4A. The converter runs in Safari, so the video isn't uploaded. Videos over about 1 GB are more reliable on a computer.
How do I get the audio from only part of a video?
Cut the part you want first, then convert the clip. On tuul.io/video-trimmer/ you set the start and end and download the clip without re-encoding, then you drop that clip on tuul.io/mp4-to-mp3/.