Convert M4A to WAV on iPhone Without an App

Nobody wants a WAV file for its own sake. What happens is that something else insists on one. A transcription service that rejects everything else. An audio editor that will import WAV and nothing else.

A DJ program, a piece of lab software, a corporate upload portal written in 2009 that has never been touched since. Or a client who said “send me the WAV” without much thought about why.

Meanwhile you have an M4A, because that is what your iPhone produces. Voice Memos records M4A. Audio pulled out of a video is usually M4A. Anything from the iTunes Store is M4A. So the two ends do not meet and here you are.

Before the how, there is one thing worth understanding, because it changes what you should expect from the result.

Converting M4A to WAV does not improve the audio

This is the single most misunderstood part of the whole task, and getting it wrong leads people to believe conversion has failed when it worked perfectly.

M4A usually contains AAC, which is a lossy format. When the recording was made, an encoder analysed the sound and threw away detail it judged you would not hear. That detail is gone. It is not compressed and recoverable, it is discarded.

WAV is uncompressed. Every sample is stored in full. That is why it is large and why editors like it.

Converting M4A to WAV takes the already-reduced audio and stores it uncompressed. The file gets roughly ten times bigger and the sound is exactly as good as it was before, which is to say no better. You are putting a photocopy into an archival frame. Useful for handing to software that demands WAV, useless as a quality upgrade.

The corollary matters too. If somebody asks you for a WAV because they want the best possible quality, converting your M4A will not give them that. What they want is the original recording, before it was ever encoded to AAC. If that original exists somewhere, go and get it.

Check whether you actually need WAV

I put this before the instructions deliberately, because a good number of people searching for this do not need to convert anything.

M4A is accepted in far more places than its reputation suggests. Most transcription services take it. Most modern editors import it. WhatsApp, email, Slack and Google Drive do not care. If the thing you are feeding is refusing your file, read the error message properly before assuming format is the problem, because size limits and corrupted downloads produce failures that look similar.

If the destination is a person rather than a machine, ask which formats they can take. “WAV” is often shorthand for “something my software will open”, and MP3 or M4A frequently qualifies. Sending a 400 MB WAV when a 40 MB M4A would have worked helps nobody.

And if the real problem is that a device or app cannot play M4A, MP3 is usually the more sensible destination, since it is smaller and even more widely supported. That route is at converting audio to MP3 on iPhone.

What iPhone can do on its own, which is very little here

Being honest about this saves you hunting. iOS has no audio format conversion anywhere in Files, Music, or Voice Memos. There is no Export As menu, no format picker when you share a Voice Memo, and no hidden setting. Voice Memos records M4A and shares M4A.

The Shortcuts app, which is already installed on your iPhone, does have audio actions and can encode to a few formats. What it offers depends on your iOS version and Apple has never documented the full list clearly. On iOS 26, which is the current shipping version, the audio encoding action exists and is worth poking at if you like building your own workflows.

The realistic summary is that iPhone alone will not turn M4A into WAV, and any article claiming there is a built in way is describing something else.

The routes that actually work

A conversion site. This is the practical answer for most people. Browser based converters handle M4A to WAV without any install, and a few of them are open source and genuinely decent.

Grabio, the free Shortcut I built, has a handoff for exactly this in its menu. Open the file in Files, tap Share, tap Grabio, and pick the conversion site from the list.

It opens vert.sh for you rather than making you find it and type things in.

To be clear about the division of labour, the conversion happens on that site rather than in Grabio, and it is a third party service, so I cannot promise it will be up or that it will handle every file you throw at it.

A computer, if you have one nearby. On a Mac, the Music app can convert. Add the file to your library, then Settings, Files, Import Settings, choose WAV Encoder, then select the track and use File, Convert, Create WAV Version. On Windows, VLC does it through Media, Convert or Save. Both are free and neither uploads anything anywhere.

Ask for the original. If the file came from somebody else and the point of the exercise is quality, this is the only route that actually delivers. Everything else is decoration on a file that has already lost what it lost.

Where your M4A came from changes the advice

Voice Memos is the most common source. Open the recording, tap the three dot menu next to it, tap Share, and save it to Files first so you have something to work with.

Voice Memos records at a modest bitrate by default, and there is a setting under Settings, then Apps, then Voice Memos, where Audio Quality can be set to Lossless.

Switch that on before recording anything you care about, since it is the one decision that genuinely affects quality and it cannot be applied retroactively.

Audio extracted from a video is the second most common source. If that is your situation, the extraction step is covered at extracting audio from a video on iPhone, and the quality ceiling is whatever the video’s audio track was.

If you are going in the other direction and need M4A rather than WAV, there is a separate guide at converting an audio file to M4A on iPhone. For file conversion generally, converting any file format on iPhone covers the wider picture.

Be ready for the file size

People are consistently surprised by this, so here are real numbers.

Uncompressed stereo audio at CD quality runs about 10 MB per minute. A one hour interview becomes roughly 600 MB. That will not attach to an email, will not fit a 100 MB upload form, and will take a while to move over anything but good wifi.

Practical consequences. Save WAV files to Files rather than into iCloud Drive if your storage is tight. Delete them once whatever needed them has consumed them, since you still have the M4A. And if you need to send one, a link is usually easier than an attachment.

What I would do

Ask whether WAV is truly required, because half the time it is not. If it is required and the audio quality matters, hunt down the original recording rather than converting a lossy copy.

If it is required and you just need the software to accept the file, use a conversion site, get the WAV, feed it in, and delete it afterwards. Then set Voice Memos to Lossless so the next recording does not put you in this position.

Get the Shortcut if you want the file handling and the handoffs in one place in your share sheet. It is free, there is no account and nothing to upgrade to.

Frequently asked questions

Can iPhone convert M4A to WAV without an app?

Not through any built in feature. Files, Music and Voice Memos have no format conversion at all. You need either a browser based converter, a computer, or a custom Shortcut you build yourself with the audio encoding action.

Does converting M4A to WAV improve the sound quality?

No. M4A is usually lossy, meaning detail was discarded when it was encoded. Converting to WAV stores that same reduced audio uncompressed, so the file grows about ten times and sounds identical. Only the original recording holds the missing detail.

Why is my WAV file so much bigger than the M4A?

WAV stores every audio sample in full with no compression, which works out at roughly 10 MB per minute for CD quality stereo. A compressed M4A of the same recording is often under 1 MB per minute. Ten times bigger is normal and expected.

What format does iPhone Voice Memos record in?

M4A. Under Settings, Apps, Voice Memos there is an Audio Quality option, and switching it to Lossless produces a much better recording. That setting only affects future recordings, so change it before anything important.

Do I really need WAV, or will another format work?

M4A and MP3 are accepted by most transcription services, editors, messaging apps and cloud drives. WAV is genuinely required by some audio software and some older upload systems. Check the error message or ask the recipient before converting, since the WAV will be roughly ten times larger.

Is there a way to convert audio on iPhone without uploading it anywhere?

Apple’s Shortcuts app includes audio actions that run using the phone’s own frameworks, so a Shortcut you build yourself keeps the work local. Browser based converters work differently, since the file goes to their service. Read the privacy policy of any site before sending it something sensitive.