When WAV is the right format
M4A (usually AAC audio in an MPEG-4 file) is efficient for listening, but some workflows need uncompressed audio:
- Audio editing in Audacity, Adobe Audition, Reaper or a video editor, where you’ll cut, process and export several times
- Transcription and speech tools that accept WAV most reliably
- Phone systems and announcements, which often specify WAV
- Samplers, DJ software and game engines that load WAV files
- Archiving a recording in a simple format that will open for decades
How to use it
Choose your M4A files or drop them on the box above. Each one is decoded and saved as WAV on your device. Download files individually, or all together as a ZIP.
Output format
- PCM WAV, the standard kind every app reads
- 16-bit, 44.1 kHz, CD quality
- Channels match the original: voice memos usually stay mono, music stays stereo
- Length is unchanged
iPhone voice memos
Voice memos are M4A files. Share them from the Voice Memos app to Files, Mail or AirDrop, then convert. Because most memos are mono speech, the WAV is about 5 MB per minute, far smaller than stereo music.
Files that won’t convert
Protected audio can’t be converted: older iTunes purchases ending in .m4p, Apple Music downloads and Audible books. Apple Lossless files, which also end in .m4a, decode most reliably in Safari; if one fails in another browser, try Safari.
Privacy
Recordings are converted inside your browser and are never uploaded. When you close the page, the audio is cleared from memory.
WAV for transcription services
Speech-to-text tools work from the sound itself, so a WAV made from a clear M4A transcribes just as accurately as the original. Two tips help most:
- Keep recordings mono. Voice memos are usually mono already, and mono WAVs are half the size of stereo with no loss for speech.
- Check the service’s size limit. At about 5 MB per minute for mono, a 90-minute interview is roughly 450 MB as WAV. If that’s too large, the M4A or an MP3 at 128 kbps is usually accepted too.
Questions
Why convert M4A to WAV?
Many audio editors, transcription services, telephone systems and hardware samplers prefer or require WAV. Editing an uncompressed copy also avoids adding compression loss each time you save.
Does the WAV sound better?
It sounds the same as the M4A. Converting can't restore detail lost when the M4A was made, but the WAV won't lose any more as you edit.
How big will the WAV be?
About 10 MB per minute for stereo, or 5 MB per minute for mono recordings such as voice memos.
Do I need anything on a Mac?
No. This works in Safari, Chrome, Edge or Firefox on Mac, Windows, Android and iPhone, with nothing to install.
Last reviewed 31 October 2026