Convert MOV to MP3

How to use it#

1. Drop a MOV onto the box above, or click it to choose one.
2. Pick a bitrate. 192 kbps suits most music and speech.
3. To keep only part of the sound, set the start and end, typed or taken from the preview with Set from video.
4. Play the MP3 in the preview, then download it.

What happens to the sound#

An iPhone records its sound as AAC, and so do most cameras and Mac screen recordings, so the sound cannot simply be copied into an MP3. To extract the audio, the page decodes it and encodes it again as MP3 with LAME, the long-established MP3 encoder, which runs inside this tab. The picture is never decoded, so even a long 4K video is quick: the time goes on the sound alone.

Each re-encode loses a little, which at 192 kbps and above is very hard to hear. Some cameras record uncompressed sound instead, and that converts the same way, with nothing lost before the MP3 encoder.

iPhone videos: spatial audio and the Photos app#

Newer iPhones record a spatial audio track beside the normal stereo one. No browser can read that format, so the stereo track goes into the MP3 and the page names the one it leaves out. A voice memo is not a MOV but an M4A, which MP4 to MP3 takes.

Choosing a video from the Photos app on an iPhone hands the page a copy made for sharing rather than the original file, which makes no difference to the sound. The MP3 is saved to Files, where it shows under Recents.

Choosing a bitrate#

128 kbps is plenty for speech, such as a lecture, a meeting, or a voice recorded on a phone, and makes the smallest file, about 1 MB a minute. 192 kbps is the default and suits music for most listeners. 256 and 320 kbps are for music you will listen to closely, at about 2 and 2.4 MB a minute.

An MP3 cannot sound better than the sound it came from. A phone records its sound already compressed, so 320 kbps from a phone video mostly makes a bigger file. When in doubt, 192 kbps is the setting nobody regrets.