MP4 vs WAV
| Property | MP4 | WAV |
|---|---|---|
| Full name | MPEG-4 Part 14 | Waveform Audio File Format |
| File extensions | .mp4, .m4v | .wav, .wave |
| Created by | MPEG (ISO/IEC 14496-14) | Microsoft and IBM |
| Introduced | 2003 | 1991 |
| Compression | Depends on the codec inside; usually lossy | Usually none: uncompressed PCM |
| Codecs inside | Usually H.264 or H.265 video with AAC audio | PCM, typically 16-bit at 44.1 or 48 kHz |
| Typical size | — | About 10 MB per minute at CD quality |
| Opens on | Every phone, computer, TV, browser, editor and social network | Every computer, phone and audio editor |
| Best for | Sharing, uploading and playing video anywhere | Recording, editing and archiving master audio |
Why convert MP4 to WAV?
WAV is the working format of audio. Audacity, Adobe Audition, Logic and every DAW import it instantly, edits are sample-accurate, and saving again never adds compression artefacts. Some transcription and speech-to-text services, phone systems and hardware samplers also ask for WAV specifically.
Converting MP4 to WAV does not make the sound better than the video’s AAC track: it decodes it once and stores the result losslessly, so no more quality is lost from that point on. The price is size. Stereo WAV at 48 kHz, the usual rate for video, takes about 11 MB per minute, so an hour-long recording is around 650 MB. Mono halves that.
If you only want to listen to or share the audio, MP4 to MP3 gives files a tenth of the size. For other audio-to-audio conversions, use the Audio Converter.