Free tool
M4A to WAV converter
Drop an M4A file here to convert M4A to WAV in your browser. An iPhone voice memo or any other AAC or Apple Lossless recording comes out as an uncompressed 16-bit WAV at its own sample rate, and nothing is uploaded.
- Free
- Works on phones
- Nothing is uploaded
Save as
Uncompressed 16-bit, for editing. About 10 MB a minute in stereo.
Drop your M4A file here, or Choose your M4A file
Any audio or video file, up to 1 GB and 2 hours. It’s converted in your browser; nothing is uploaded.
MP3 encoding by LAME, open-source software.
Is the memo a meeting or an interview? NoteOwl imports the M4A itself, with no WAV needed, and transcribes it on your Mac with each speaker labelled.
How it works
How do you convert an M4A file to WAV?
Keep WAV selected and drop the M4A. Your browser decodes the AAC sound and the page lays every sample down as 16-bit PCM, at the memo’s own rate unless you untick the box. A five-minute memo was done in 0.7 seconds in Chrome.
- 1
Decide on the rate
Ticked, the WAV matches the M4A’s sample rate. Unticked, every WAV is written at 44.1 kHz, the rate of an audio CD.
- 2
Add the M4A
Drag it in from Finder, or pick it from the Files app on an iPhone. AAC memos work in Chrome and Safari; lossless ones need Safari.
- 3
Save the WAV
Listen first, then download. The memo’s name is kept with .wav on the end, and the M4A is left untouched.
How much bigger is a voice memo once it becomes a WAV?
About twelve times bigger. WAV keeps every sample with no compression, so a minute of 48 kHz mono fills 5.8 MB however small the M4A was. A five-minute, 2.35 MB AAC memo turned into a 28.8 MB WAV.
- 5 min, AAC, mono, 48 kHz, 64 kbps, 2.35 MB
- WAV written48 kHz mono (rate kept)
- Size28.8 MB
- Time, Chrome / WebKit0.7 s / 1.9 s
- Same memo, rate box unticked
- WAV written44.1 kHz mono
- Size26.5 MB
- Time, Chrome / WebKit1.1 s / 1.9 s
- 1 min, Apple Lossless, mono, 48 kHz, 16-bit, 1.1 MB
- WAV written48 kHz mono
- Size5.8 MB
- Time, Chrome / WebKitCan’t decode / 0.18 s
| Memo | WAV written | Size | Time, Chrome / WebKit |
|---|---|---|---|
| 5 min, AAC, mono, 48 kHz, 64 kbps, 2.35 MB | 48 kHz mono (rate kept) | 28.8 MB | 0.7 s / 1.9 s |
| Same memo, rate box unticked | 44.1 kHz mono | 26.5 MB | 1.1 s / 1.9 s |
| 1 min, Apple Lossless, mono, 48 kHz, 16-bit, 1.1 MB | 48 kHz mono | 5.8 MB | Can’t decode / 0.18 s |
What kind of sound does an M4A file hold?
Usually AAC, a lossy codec that keeps speech small: the five-minute test memo carries 64 kbps of it in 2.35 MB. Some M4As hold Apple Lossless instead, which keeps every sample; Voice Memos records that when its Audio Quality setting is Lossless.
Both kinds end in .m4a and look identical in Finder. The converter tells you which you have as soon as it reads the file, listing the codec, sample rate and channels beside its size and length.
Why won’t a lossless voice memo convert in Chrome?
Chrome has no Apple Lossless decoder, so the converter stops and says so, pointing you to Safari. Safari decodes Apple Lossless and converts it, reading the whole file in one go, which works for recordings up to 30 minutes long.
Memos recorded with Audio Quality set to Compressed are standard AAC files: those stream in either browser, up to 2 hours.
Why do editors and samplers ask for WAV instead of M4A?
Because WAV is plain PCM that needs no decoder at all. Many hardware samplers and some upload forms take WAV but not M4A, and every editor, from GarageBand and Logic Pro to Audacity on Windows or Linux, opens a WAV the same way.
Does a WAV made from an M4A sound any better?
Not from an AAC memo. Whatever AAC discarded at recording time is gone, and the WAV holds exactly what is left. From a 16-bit Apple Lossless memo the WAV matches the recording sample for sample, so nothing is lost either way.
What a WAV adds is freedom to edit. Saving a WAV again costs nothing, while every fresh save to AAC trims a little more detail, so cut and clean the memo as WAV and compress it only at the end.
Do you need a WAV before a memo can be transcribed?
Not for NoteOwl. It imports M4A recordings as they are and transcribes them on your Mac with on-device AI models, telling the speakers apart and keeping each transcript searchable. WAV imports too, so convert only when some other app needs it.
For Apple’s built-in options beside NoteOwl’s, see how to transcribe a voice memo on a Mac. Dictation into any app is free.
FAQ
Questions about converting M4A files to WAV
Is my voice memo uploaded when I convert it?
No. Your own browser decodes the M4A and the page assembles the WAV on your device, so nothing is uploaded at any point. A memo of a private conversation stays on your phone or computer, and no account is needed.
Can I convert M4A to WAV on an iPhone?
Yes, in Safari. Tap Choose file, pick the memo in the Files app and wait a moment for the WAV; Safari puts the download in the Downloads folder of Files. Safari also reads lossless memos, up to 30 minutes long.
Why is the WAV twelve times the size of the M4A?
AAC squeezes a voice memo hard, to 64 kbps in the test file, while WAV stores 16-bit samples with no compression at all: 768 kbps for 48 kHz mono. Five minutes went from 2.35 MB as M4A to 28.8 MB as WAV.
Which sample rate will the WAV have?
The M4A’s own, while Keep the original sample rate is ticked; unticked, it is 44.1 kHz. The 48 kHz test memo stayed at 48 kHz with the box ticked, and came out 8% smaller, at 26.5 MB, at 44.1 kHz.
Does it work with M4A files that aren’t voice memos?
Yes. Any M4A with AAC sound converts, HE-AAC included, and so do M4B audiobooks and the audio-only files Zoom saves beside a recording. Apple Lossless M4A files convert in Safari.
How long a memo can it convert?
AAC memos up to 2 hours or 1 GB, in Chrome and Safari alike; lossless ones in Safari only, up to 30 minutes. Two hours of 48 kHz mono comes to about 691 MB of WAV, held in the page until you save it.
Keep exploring
More audio converters
- Audio converterConvert audio and video files to MP3, WAV, M4A or OGG in your browser: M4A, FLAC, AIFF, OGG, Opus, WebM, MP4 and MOV in; nothing is uploaded
- FLAC to MP3 converterConvert FLAC to MP3 in your browser at 128, 192 or 320 kbps, 24-bit and 96 kHz files included; nothing is uploaded
- WebM to MP3 converterConvert WebM to MP3 in your browser: the Opus or Vorbis sound of a browser or screen recording, saved as an MP3; nothing is uploaded
- AIFF to MP3 converterConvert AIFF and AIF files from GarageBand, Logic and other Mac apps to MP3 in your browser; nothing is uploaded
Related
- M4A to MP3 converterConvert M4A to MP3 in your browser, iPhone and Mac voice memos included, at 128, 192 or 320 kbps; nothing is uploaded
- Voice memo to textHow to turn a Voice Memos recording into text on a Mac, with Apple’s own tools and with NoteOwl
- Voice notes on your MacVoice notes and dictations saved as searchable text on your Mac, with the raw words beside the polished version; free
Voice memos into searchable notes, on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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