Convert M4A to WAV Online Free
Convert your .m4a files to .wav format. Free, fast, and processed entirely in your browser — your files never leave your device.
Convert M4A to WAV — for DAWs, transcription, and pro audio workflows
M4A to WAV is the conversion you do when you need to drop an iPhone Voice Memo, GarageBand export, or QuickTime recording into a tool that won't take M4A: a DAW like Pro Tools or Reaper, a transcription pipeline that demands PCM, a video editor that mishandles AAC, or a sample library workflow. WAV is the universal pro-audio format, so this conversion is mostly about compatibility, not quality. Here's how to do it cleanly, what to expect for file size, and the one trap to avoid.
When converting M4A to WAV is the right call
- You're importing an iPhone recording or GarageBand export into a DAW that doesn't decode AAC efficiently (older Pro Tools, some Reaper plugins, certain hardware-based DAWs).
- You're feeding a transcription tool that explicitly wants PCM/WAV input. Most modern services (Whisper, Descript, Otter) accept M4A, but some specialty forensic-audio and broadcast-spec tools insist on WAV.
- You're sending audio to a mastering engineer or post-production team. Pro contexts always work in WAV — even if your source is an iPhone recording, deliver as WAV.
- You need to do sample-accurate editing. AAC frames don't align cleanly to sample boundaries; WAV does.
- You're prepping audio for CD burning or a broadcast spec that requires uncompressed PCM.
When you should NOT convert M4A to WAV
- You think it'll improve quality. M4A is lossy; WAV is uncompressed. Converting wraps the (already-degraded) AAC audio in a 10× larger uncompressed container. Your file gets huge but doesn't sound better.
- You're just moving the file between Apple devices. M4A is the native Apple format; WAV is overkill.
- Storage is tight. M4A files are typically 1/10 the size of WAV. If you're working off a small SSD or sending audio over a slow connection, this conversion is expensive.
- Your M4A has DRM (from Apple Music subscription). No tool can convert it. Only Apple's own apps can play it back.
How much bigger the WAV will be
M4A is highly compressed (lossy AAC). WAV is uncompressed. The output WAV is typically 5-10× the source M4A — depends mostly on the M4A's bitrate.
| Duration | M4A | WAV | Note |
|---|---|---|---|
| 1 minute (Voice Memo, 64 kbps mono M4A) | ~0.5 MB | ~5 MB (16-bit mono WAV) | 10× larger |
| 1 minute (256 kbps stereo M4A) | ~1.9 MB | ~10.1 MB (16-bit stereo WAV) | 5.3× larger |
| 10 minutes (256 kbps M4A) | ~19 MB | ~101 MB | Comfortably handled by any DAW |
| 1 hour (Voice Memo) | ~28 MB | ~300 MB (mono WAV) | Watch your storage and email limits |
Source: M4A at typical bitrates. Target: 16-bit / 44.1 kHz stereo WAV (~1411 kbps). For Voice Memos at 64 kbps mono, target may be 16-bit / 44.1 kHz mono (~706 kbps).
Where WAV works (basically: every pro audio tool)
Works with
- Every desktop DAW: Pro Tools, Logic, Ableton, FL Studio, Reaper, Cubase, Audacity
- Every video editor: Premiere, Final Cut, DaVinci Resolve, iMovie
- Every transcription tool that has explicit WAV/PCM mode: Whisper, Otter, broadcast-spec services
- Sample libraries, hardware samplers (MPC, Maschine, Ableton Push)
- CD burning, broadcast delivery, mastering studios
Does not work with
- Sharing on social media or chat — WAV is too big and most platforms re-encode anyway
- Phone storage — WAV's size makes it impractical for music libraries
- Web embeds and streaming — bandwidth cost is unjustified vs M4A or MP3
How to convert M4A to WAV
Convert with WaveSieve (browser, free, no upload)
Quickest path. Conversion runs in your browser via FFmpeg.wasm — your file never leaves your device, no account needed.
- Drop your M4A file onto the upload area at the top of this page. Up to 100 MB per file.
- In the converter, change the output format to WAV.
- Click "Convert to WAV" — decoding takes 5-30 seconds depending on file length.
- Click "Download" to save the WAV.
Convert with macOS QuickTime / Music app (Mac only)
On a Mac, the built-in tools handle this without extra software.
- Open Music app. Music → Settings → Files → Import Settings → set "Import Using" to "WAV Encoder".
- Drag your M4A into the library, or File → Import.
- Right-click the imported track → "Convert" → "Create WAV Version".
- The WAV appears next to the M4A. Right-click → "Show in Finder" to grab the file.
Convert with FFmpeg (command line, batch)
For batch jobs, especially Voice Memos exported in bulk from iPhone.
- Install FFmpeg: brew install ffmpeg (macOS), winget install ffmpeg (Windows), or sudo apt install ffmpeg (Linux).
- Open a terminal in the folder with your M4As.
- Single file at 16-bit / 44.1 kHz: ffmpeg -i input.m4a -c:a pcm_s16le -ar 44100 output.wav
- 24-bit / 48 kHz for video work: ffmpeg -i input.m4a -c:a pcm_s24le -ar 48000 output.wav
- Whole folder: for f in *.m4a; do ffmpeg -i "$f" -c:a pcm_s16le -ar 44100 "${f%.m4a}.wav"; done
Things that surprise people
WAV does not restore quality the M4A already lost
AAC encoding inside the M4A is lossy — it threw away frequencies the encoder judged inaudible. Converting to WAV decodes that AAC into raw PCM and stores it uncompressed. The audio data is exactly the same as what the AAC decoder produced; the WAV is just a much bigger container around it. WAV gives you compatibility with pro tools, not improved fidelity.
Voice Memos record at 22.05 kHz — you may get unexpected sample rates
iPhone Voice Memos default to 22.05 kHz mono AAC at 64 kbps. If you convert to WAV at 44.1 kHz, FFmpeg or whatever tool you use will upsample. The audio still sounds the same as the source, but you're storing 2× the samples for nothing. Either keep the source rate (22.05 kHz WAV) or accept the larger file as the cost of compatibility with downstream tools that expect 44.1.
DRM-protected M4A can't be converted
If your M4A is from Apple Music subscription, it has FairPlay DRM. No conversion tool can open it — neither WaveSieve, FFmpeg, nor anything else. Only Apple's own apps can decode it. To get a WAV of that audio, you need a different source (CD, separate purchase, original master).
Frequently Asked Questions
What's the bit depth and sample rate I should pick for WAV output?
Default is 16-bit / 44.1 kHz (CD quality). For film/TV post-production, switch to 24-bit / 48 kHz — that's the broadcast spec. For voice transcription, mono 16-bit / 16 kHz is often plenty (Whisper's preferred input). The right setting is whatever your downstream tool wants.
Will the metadata (recording date, title) survive?
Mostly no. WAV has limited metadata support — it can store basic info via the BWF/RIFF spec, but most tools strip it during conversion. M4A's rich metadata (chapter markers, recording location, embedded album art) does NOT survive to WAV. If metadata matters, keep the M4A alongside the WAV.
Should I convert all my Voice Memos to WAV for archival?
Probably not. WAV will be 10× the size of your Voice Memo M4A library. The audio quality is identical (the lossy compression already happened on iPhone). Keep the M4As as your archive; convert specific ones to WAV only when you need to feed a tool that requires it.
Why do some tools struggle with M4A but not WAV?
M4A requires AAC decoding (a non-trivial codec) and proper MP4 container parsing. Older or specialized tools sometimes only support WAV (raw PCM is dead simple to read). Pro audio software at high sample counts also benefits from WAV's straightforward layout — no decode CPU overhead during playback.