MP4 to WAV

Convert MP4 to WAV to get the sound of a video as an uncompressed file that any audio program opens.

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How to convert MP4 to WAV

  1. Tap Choose an MP4 video and pick the file.
  2. To keep only a section, type its start and end under Part to save.
  3. Press Convert to WAV, listen to the result, then save or share it.

Why WAV, when the video has compressed sound

The sound in an MP4 is nearly always AAC, a compressed format. Saving it as WAV does not improve it. What WAV gives you is a file that every audio tool reads directly and that can be edited and saved again and again with no further loss.

  • Audio editors and music software work on uncompressed sound internally. A WAV loads instantly and lines up exactly, sample for sample.
  • Transcription and speech tools often ask for WAV, because it needs no decoding.
  • Samplers, loop stations and hardware recorders commonly accept WAV only.
  • Video editing. Sound cleaned up in an audio program is brought back into the edit as WAV to avoid compressing it twice.

What the WAV is like

PropertyValue
Bit depth16-bit, the same as a CD
Sample rateThe same as the video, usually 48 kHz or 44.1 kHz
ChannelsThe same as the video: mono or stereo
Size in stereoAbout 10 MB for each minute
Size in monoAbout 5 MB for each minute

The sample rate is not changed, so the sound stays in step with the picture if you bring it back into a video project.

Long videos make large files

An hour of stereo sound is around 600 MB as WAV. If you only need part of it, type the start and end under Part to save before converting, for example 12:30 to 15:00. Sound is read from an MP4 a piece at a time, so the length of the video is not a problem in itself, but the WAV format cannot exceed 4 GB, which is a little over six hours in stereo.

If you do not need uncompressed sound

For listening, sharing or archiving, a smaller file is more practical. Video to audio can copy the original AAC sound out as an M4A file with no loss at all, at about a tenth of the size of a WAV.

Things that can stop a conversion

  • A video with no audio track. The tool tells you there is no sound to save.
  • Sound in Dolby Digital or DTS, which browsers cannot decode.
  • A device that is very low on memory for a very long recording. Save a part at a time.

Questions

Does MP4 to WAV improve the sound quality?

No. The WAV holds exactly what the video's sound decodes to. Its advantage is that nothing more is lost when it is edited and saved.

How big will the WAV be?

About 10 MB a minute in stereo and 5 MB a minute in mono.

Can I save only part of the audio?

Yes. Type the start and end times under Part to save.

Is the WAV 16-bit or 24-bit?

16-bit, at the same sample rate as the video.

Does it work with long videos?

Yes. The sound is read a piece at a time. The WAV format itself tops out at 4 GB, a little over six hours of stereo.

Last reviewed .

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