What happens when you convert MP4 to MP3
- MP3 holds sound only, so the picture is discarded and the soundtrack is encoded as MP3 at 192 kbps.
- If the MP4 has several audio tracks, the first one is used.
How to convert MP4 to MP3 online
- Press "Choose MP4 files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
- Adjust the settings if you need to: the bitrate controls quality and size. The defaults suit most people.
- Press "Convert to MP3". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
- Save each MP3 with its download button. Close the tab and every trace of the files is gone from memory.
Why convert MP4 to MP3?
MP4 files usually come from phone videos, YouTube uploads, social media and streaming. People convert them to MP3 because MP3 plays in every phone, car stereo, smart speaker and website, and it keeps music small.
In short, MP4 is good at what it was made for, and MP3 is the more practical choice when the file has to play on another device or app. MP4 plays in every browser, phone and smart TV, while MP3 plays in every browser, phone, car stereo and media player.
How to convert MP4 to MP3 on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your MP4 files in from File Explorer, and press Convert. Each MP3 is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert MP4 to MP3: choose Media, then Convert / Save.
On a Mac
Safari, Chrome and Firefox all work. Drag the MP4 files from Finder onto the drop zone and the MP3 files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose MP4 files. You can pick from Photos or from the Files app. The converted MP3 appears in Files, in the Downloads folder.
On Android
Open the page in Chrome, tap Choose MP4 files and pick them from Files or your gallery. The MP3 is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.
Best settings for MP4 to MP3
MP3 is a lossy format, so the bitrate decides both the sound quality and the file size. Size grows in a straight line with bitrate: double the bitrate and the file doubles.
| Bitrate | Size per minute | Good for |
|---|---|---|
| 320 kbps | about 2.4 MB | the highest quality, for music you will keep |
| 256 kbps | about 1.9 MB | excellent music quality |
| 192 kbps | about 1.4 MB | the default: transparent for most listeners |
| 128 kbps | about 1.0 MB | good for music on the go and for podcasts |
| 96 kbps | about 0.7 MB | speech and audiobooks |
| 64 kbps | about 0.5 MB | voice notes and spoken word only |
The MP4 was already compressed, so pick a bitrate at least as high as the original. Going higher does not add quality back, it only makes the file bigger.
MP4 vs MP3: the differences
| MP4 | MP3 | |
|---|---|---|
| Full name | MPEG-4 Part 14 video | MPEG-1 Audio Layer III |
| Type | video | audio |
| Created by | the Moving Picture Experts Group | the Fraunhofer Institute |
| First released | 2001 | 1993 |
| Compression | Lossy | Lossy |
| Usually contains | H.264 or H.265 video with AAC audio | MP3 audio, typically 128 to 320 kbps |
| In a browser | plays in every browser, phone and smart TV | plays in every browser, phone, car stereo and media player |
| Common uses | phone videos, YouTube uploads, social media and streaming | music libraries, podcasts and anything that has to play everywhere |
| MIME type | video/mp4 | audio/mpeg |
About MP4 and MP3 files
What is an MP4 file?
MP4 is the most widely supported video format, and H.264 video with AAC audio inside it plays on essentially every device made in the last fifteen years.
What is an MP3 file?
MP3 is the most widely supported audio format there is, which is its whole appeal. At 320 kbps most listeners cannot tell it from the original; at 128 kbps cymbals and applause start to smear.
MP4 to MP3 not working? Common problems
- The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
- The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
- Song titles are missing. Tags such as title and artist are copied when MP3 can store them, but cover art is not carried over.
Convert MP4 to MP3 with ffmpeg
This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent MP3 with the same kind of settings:
ffmpeg -i input.mp4 -vn -c:a libmp3lame -b:a 192k output.mp3Replace input.mp4 with the name of your file. For a whole folder of MP4 files, run the command in a loop, or drop them all on the converter above, which processes them one after another.
MP4 to MP3 converter FAQ
Will I lose quality converting MP4 to MP3?
The sound is re-encoded as MP3 at 192 kbps, which is transparent for most listeners. The picture is not kept.
Why is the MP3 a different size from the MP4?
The MP3 is much smaller, because the video stream, usually most of the file, is dropped.
Are my MP4 files uploaded anywhere?
No. The conversion runs inside this browser tab using ffmpeg compiled to WebAssembly, so your files stay on your device. You can disconnect from the internet after the page and converter engine have loaded and it still works.
Can I convert several MP4 files to MP3 at once?
Yes. Select or drop as many files as you like; they are converted one after another and each gets its own download button.
How do I open an MP3 file?
MP3 plays in every browser, phone, car stereo and media player. MP3 is common for music libraries, podcasts and anything that has to play everywhere.
Is this MP4 to MP3 converter free?
Yes. There is no sign-up, no watermark and no limit on how many files you convert. The site is paid for by advertising, and because conversions run on your device there is no server cost per file.
Can I convert MP4 to MP3 on my phone?
Yes. The converter works in Safari on iPhone and iPad and in Chrome on Android. Converted files are saved to the Downloads folder.