M4A to FLAC on iPhone

Safari on iOS 15.4 and newer runs the converter completely, on the phone itself. There is no App Store download — and no converter app quietly uploading your recordings to its own servers. M4A files convert to FLAC here the same way — nothing to install.

If the file is in Voice Memos or Photos, tap the share icon and choose 'Save to Files' first — that makes it visible to Safari's file picker. The converted file lands in Files (Downloads by default), from where you can share it into Messages, Mail, or any app. Your M4A comes out as FLAC, ready to use straight away.

The M4A files people convert on an iPhone almost always originate from iPhone Voice Memos, iTunes libraries, GarageBand exports, and Apple Music downloads, and M4A is Apple's default, and while it plays widely, many DAWs and editors refuse it or import it with wrong durations — which is precisely why they're stuck on the phone until you convert them to FLAC.

Budget for roughly 5 MB per minute — about 4× what the M4A took. You're trading disk for a format that tools actually accept. What M4A threw away is unrecoverable. FLAC preserves what's left perfectly, which is the most any format can do for it.

M4A to FLAC is a common iPhone snag specifically because M4A is Apple's default, and while it plays widely, many DAWs and editors refuse it or import it with wrong durations, and FLAC is what your other apps and devices expect. Apple gives you no built-in way to convert audio at all, so the App Store is full of converter apps — many upload your recording to their own servers, show ads against it, and want a subscription. Doing it in Safari means the M4A file is processed on the phone itself and stays there, which matters when it is a voice memo, an interview, or a recording of your own family.

Your M4A file never leaves the handset. For iPhone that is the whole argument: iPhone Voice Memos are usually personal, and the App Store alternative frequently ships them to a company's servers as the price of a free conversion. Processing the M4A-to-FLAC conversion on-device means there is no server to trust in the first place.

The M4A on your drive almost certainly started life in iPhone Voice Memos, and M4A is Apple's default, and while it plays widely, many DAWs and editors refuse it or import it with wrong durations. FLAC is the destination when you need uncompressed, edit-ready audio that every DAW and editor accepts. Yes, it gets larger — around 4× — since you're unpacking the audio rather than compressing it. Keep the M4A for storage and use the FLAC as the working copy. One honest note on this exact pair: M4A is already lossy, so moving to FLAC cannot restore detail the M4A encoder discarded — it hands you an uncompressed container, not better audio, and the value is a loss-free chain from here on.