M4A vs WAV: which do you need?
WAV keeps every sample exactly and is big. M4A compresses, usually with AAC, and is small. Which one you want depends on whether you are editing or listening.
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Quick answer: WAV is uncompressed: one minute of stereo music took 10.58 MB as WAV and 1.93 MB as a 256 kbps M4A, five and a half times less. Use WAV for recording, editing, audio CDs and anything that asks for WAV; use M4A for listening, sending and storing. Converting an M4A to WAV makes it editable in more programs but cannot restore the detail AAC left out.
Updated
Choose WAV when
- You record or edit: every save and effect stays exact.
- A program, sampler, CD burner or upload form asks for WAV.
- You make a master to export other formats from later.
Choose M4A when
- You listen, share or store recordings: a fifth of the space.
- It is a voice memo or a phone recording.
- The file has to fit in an email or a chat.
The same recordings, measured
| Recording | WAV | M4A (AAC) |
|---|---|---|
| 1 min of music, stereo | 10.58 MB | 1.93 MB at 256 kbps · 0.98 MB at 128 kbps |
| 1 min of speech, mono | 5.29 MB | 0.50 MB at 64 kbps |
One minute of the Sintel trailer soundtrack (stereo, 44.1 kHz), made with standard free software on 20 October 2026. Sintel © Blender Foundation, CC BY 3.0. One minute of a person reading aloud (mono), made with standard free software on 20 October 2026.
How it works
- Drop your audio fileMP3, M4A, FLAC, OGG and more. It stays on your computer.
- ConvertThe sound is unpacked into a WAV file, with nothing added or changed.
- Download the WAVOpens in every audio editor, sampler and recording app.
Why WAV is so big
WAV stores every sample as it is: 44,100 per second per channel, 16 bits each, about 10 MB a minute for stereo music. Nothing is thrown away, and nothing is compressed. An M4A usually holds AAC, which leaves out detail that is hard to hear and comes out five to ten times smaller.
When to convert M4A to WAV
When an editor, sampler, DJ program or upload form will not take M4A, or when you are about to edit and re-save many times. The WAV sounds exactly like the M4A it came from: no better, no worse, just bigger. The converter above makes a standard 16-bit WAV in your browser.
Lossless without the size
If you need exact sound but less space, FLAC or Apple's lossless M4A (ALAC) store the same samples in roughly half the size of a WAV.
Measured, not promised
From our tests in Chrome on a 2019 Intel MacBook, October 2026. See all results.
Why your audio never leaves your computer
Online converters upload your file to their servers, convert it there and send it back. That is slow for long recordings, so free plans cap the length or the number of files, and your recording sits on someone else's computer.
Here your own computer does the work, inside this tab. Nothing is uploaded, so there is nothing to cap: no length limit, no daily limit and no sign-up.
Questions
Does converting M4A to WAV improve quality?
No. It keeps exactly what the M4A has, in a format more programs edit easily.
Is WAV better than M4A?
WAV is exact, so for recording and editing yes. For listening, a 256 kbps M4A is very hard to tell apart, at a fifth of the size.
Why is my WAV ten times bigger?
WAV is uncompressed. The table shows one minute of music at 10.58 MB as WAV against 0.98 MB as a 128 kbps M4A.
Can I convert several files at once?
Yes. Choose or drop several files together. They are converted one after another with the same settings, and you can download each one or all of them in one ZIP.
Is it really free?
Yes. Your computer does the work, so a file costs us nothing to convert. No account and no limits.
Is my file uploaded?
No. It is converted inside this browser tab and saved straight back to your computer.
Which browsers work?
Recent Chrome, Edge and Safari on a computer.
Can I use a video file?
Yes. Drop a video and you get its sound.