MP4 to MP3
Turn the sound of an MP4 video into an MP3 file. The video never leaves your device: ffmpeg.wasm reads it and writes the MP3 inside this browser tab.
Click or drop a video file hereChoose a video file
How to convert MP4 to MP3
- Choose or drop an MP4 file. MOV, MKV, WebM, AVI, and 24 other video formats work the same way: each one was tested with a real extraction. An M2V file holds only a picture, so it has no sound to extract.
- Keep MP3 as the target format and pick a quality: 192 kbps is selected first; 128 kbps makes a smaller file, for example for speech; 256 or 320 kbps keeps more detail.
- Select "Extract audio". The first time, the ffmpeg.wasm engine, about 10 MB, is downloaded too.
- Listen to the result, then select "Download" to save the MP3, named after the video.
MP4 or MP3: what changes
An MP4 file holds a picture track and usually a sound track. An MP3 file holds sound only. Extracting keeps the sound, encoded again as MP3, and leaves the picture out: the file is much smaller and plays in any music player.
What happens to your video
The video is read and converted by ffmpeg.wasm in this tab. Neither the video nor the MP3 is uploaded. The engine itself is downloaded from unpkg.com, a public code host, the first time you use it. Only the sound is decoded and encoded: the picture is skipped, which keeps the work short.
Good to know
- Quality: MP3 compresses the sound again, so some detail goes; a higher bitrate keeps more. No format can restore what the video's own sound track already lost. To keep every detail, choose WAV or FLAC: they store the decoded sound without loss.
- Mono and stereo: the page sends no channel setting, so mono stays mono and stereo stays stereo.
- File size: the page sets no limit, but the whole video is copied into the tab's memory, so a very large file can fail. Cut it with Trim Video first.
- One video at a time, and always its whole sound track: to keep only part of it, cut the MP3 afterward with Trim Audio.
- Other formats: the same page also writes WAV, AAC, FLAC, OGG, M4A, Opus, WMA, AIFF, ALAC, AC3, M4R (iPhone ringtone), M4B (audiobook), MP2, WavPack, CAF, AU, MKA, and AMR (phone voice). AMR is the only one made by our media service: for AMR, the video is sent to it, then deleted.
Frequently asked questions
Is MP4 to MP3 free?
Yes. There is no sign-up, no watermark, and no daily limit: the work runs on your own device.
Does it work on iPhone?
Yes, in Safari. Save the MP3 with "Download", or keep it in Files or send it with "Save or share".
What if my video has no sound?
The page tells you that the video has no sound track: there is no audio to extract. This is often the case with screen recordings.
Can I make an iPhone ringtone from an MP4?
Yes. Choose "M4R (iPhone ringtone, AAC)" instead of MP3. An iPhone ringtone lasts about 40 seconds at most: cut the M4R to that length with Trim Audio, which keeps the M4R format. Then add it to the iPhone with GarageBand (share the sound as a ringtone) or from a computer, with Finder or iTunes.
Why is my MP3 smaller than the video?
The picture is left out, and MP3 compresses the sound. At 192 kbps, a minute of sound takes about 1.4 MB.