MP3 vs WAV vs M4A: Which Audio Format Should You Use?

MP3, WAV and M4A are the three audio formats you'll meet most often. They differ in one trade-off: file size against how much of the original sound is kept. Here's what each one is, how big the files get, and which to choose for the job in front of you.

The short answer

Use MP3 when the file has to play anywhere: old players, car stereos, upload forms. Use M4A when you want the best quality for the size and your devices are reasonably modern. Use WAV only for editing or when software specifically asks for it, because the files are about ten times bigger.

MP3

MP3 is a lossy format from the 1990s. It throws away sound the ear is unlikely to notice. At 192 kbps it sounds transparent to most people on ordinary equipment, and a minute takes about 1.4 MB.

Its big strength is compatibility: every phone, computer, browser, car stereo and editing app plays MP3. That's why forms, job portals and podcast services often ask for it.

M4A (AAC)

M4A is an MP4 container holding AAC audio, the codec used by iPhones, YouTube and most streaming services. AAC is more efficient than MP3: 128 kbps AAC sounds about as good as 160 to 192 kbps MP3, and the advantage is biggest at low bitrates like 64 kbps.

M4A plays on Apple devices, Android, Windows 10 and later, and all modern browsers. iPhone Voice Memos and most MP4 videos already use AAC, so saving their audio as M4A can be done without re-encoding at all.

WAV

WAV stores audio uncompressed (PCM). Nothing is thrown away, so it's the natural format for recording and editing, but CD-quality stereo takes about 10 MB per minute: a 4-minute song is around 40 MB.

Converting an MP3 to WAV doesn't bring back lost detail. The WAV just holds the decoded MP3. WAV is worth it when you're recording, editing or mastering, or when a program only accepts WAV.

File size at a glance

Per minute of stereo audio: WAV (44.1 kHz, 16-bit) about 10 MB; MP3 at 320 kbps about 2.4 MB; MP3 at 192 kbps about 1.4 MB; MP3 or M4A at 128 kbps about 0.96 MB; M4A at 64 kbps about 0.48 MB. The same rule applies to any compressed audio: size equals bitrate times length.

Which to choose

Sharing a recording or song with anyone: MP3 at 128 to 192 kbps.

Music library on iPhone or in Apple Music: M4A at 256 kbps.

Voice notes, lectures and meetings you want small: M4A or MP3 at 64 kbps.

Editing in a DAW or video editor: WAV, then export the final mix to MP3 or M4A.

Archiving a CD or master: a lossless format such as FLAC or WAV, and make MP3s from it.

Whatever you pick, keep your original file. Every conversion between lossy formats loses a little more.

Frequently asked questions

Is M4A better than MP3?

At the same bitrate, yes: AAC in M4A sounds slightly better, especially at low bitrates. MP3 is still more compatible with old devices and some upload forms.

Is WAV better quality than MP3?

A WAV recording is lossless, so it keeps more detail than an MP3 of the same recording. But converting an existing MP3 to WAV doesn't improve it.

Which audio format is smallest?

Of these three, M4A at a low bitrate like 64 kbps gives the smallest file that still sounds good. WAV is by far the largest.

How do I convert between MP3, WAV and M4A?

ClipUtils' Audio Converter converts any of them, and the audio inside videos, in your browser without uploading. There are also dedicated WAV to MP3 and MP3 to WAV pages.

Related tools: Audio Converter · WAV to MP3 · MP3 to WAV · Compress Audio