M4A vs WAV
WAV is uncompressed CD-quality audio, five to ten times the size of an M4A that most people cannot tell apart from it. Use WAV for recording and editing, and M4A for listening, sharing and keeping music on a phone.
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Choose M4A when
- Music on a phone, in Apple Music or iTunes.
- Voice memos and recordings you will share.
- Anywhere storage or upload size matters.
Choose WAV when
- Recording, editing and mixing, where every step must be lossless.
- Delivering audio to a studio, a video editor or a broadcaster.
- Software or hardware that only reads uncompressed audio.
What M4A actually is
M4A is an MP4 container holding an AAC stream. AAC was designed as the successor to MP3 and it delivers clearly better sound at the same bitrate, particularly below 128 kbps. It is the default for Apple Music, YouTube audio and most streaming services.
M4A, M4B, M4R and AAC are largely the same thing with different extensions. Renaming usually works, though it is not something to rely on.
What WAV actually is
A WAV file normally holds uncompressed samples exactly as they were recorded: about 10 MB per minute of CD-quality stereo. There is no decoding step, no quality loss, and no ambiguity, which is why it is the working format in recording and editing.
Converting an MP3 to WAV makes the file ten times larger without recovering anything. The detail the MP3 discarded is gone.
M4A and WAV side by side
| M4A | WAV | |
|---|---|---|
| Extension | .m4a | .wav |
| Media type | audio/mp4 | audio/wav |
| Inside the file | AAC | uncompressed PCM |
| Compression | Lossy | Lossless |
| One minute of stereo | 1 to 1.9 MB | about 10 MB |
| Plays on | Apple devices, Android, browsers and most modern players | every editor, DAW and operating system |
| We can write it | Yes | Yes |
Questions
Is M4A lower quality than WAV?
An M4A holding AAC is lossy, so strictly yes; at 256 kbps the difference is inaudible to most people. An M4A can also hold Apple Lossless, which is identical to the WAV.
How big is a minute of WAV?
About 10 MB at CD quality (44.1 kHz, 16-bit stereo), against roughly 1 to 2 MB for an M4A.