AAC to M4A Converter
Wrap raw AAC audio in an M4A container so it plays cleanly in iTunes, Apple Music, and across Apple devices. Runs entirely in your browser — nothing is uploaded.
Drop your AAC file here or click to browse
AAC (.aac) · Max 20 MB
Free — 10-second preview, 5 conversions/month. Upgrade for unlimited
What is AAC?
Advanced Audio Coding. Successor to MP3 with improved compression. Widely used in streaming services.
What is M4A?
Apple's preferred audio format. Better quality than MP3 at same bitrate. Default for iTunes and Apple devices.
Why Convert AAC to M4A?
AAC and M4A hold the same kind of audio — Advanced Audio Coding — but they package it differently, and that packaging is what trips people up. A raw .aac file is a bare ADTS stream with no container around it, which is why iTunes, Apple Music, the Music app on iPhone, and plenty of other players either refuse to import it or handle it awkwardly (no clean metadata, no reliable seeking, sometimes no playback at all). M4A is the container Apple actually expects: it's an MP4 wrapper around the very same AAC audio, with proper support for titles, artwork, and accurate scrubbing. Converting AAC to M4A puts the audio in the box that Apple software wants, so a raw AAC file you downloaded or exported drops straight into your library and behaves like every other track. Because both formats use AAC, this is essentially a re-wrap: you're not throwing away quality by moving to a lossy format, you're moving lossy AAC into the container that plays nicely with Apple's ecosystem. This converter reads the AAC stream and writes a standard M4A with FFmpeg compiled to WebAssembly, entirely inside your browser — your file is never uploaded to a server. It's the quickest way to make a stray .aac file feel at home in iTunes, Apple Music, GarageBand, or on your iPhone, without installing anything.
Who Uses This Converter
Add AAC files to your Apple library
Raw .aac files often won't import into iTunes or Apple Music. M4A drops straight into your library and plays like any other track.
Get proper metadata & artwork
M4A supports titles, artists, and cover art that bare AAC streams can't carry reliably. Convert to tag your audio properly.
Reliable seeking and scrubbing
The M4A container adds the index that lets players seek accurately — handy for long recordings and audiobooks.
Use in GarageBand and Apple apps
Apple's creative apps expect M4A. Convert your AAC audio so it imports without complaints.
Frequently Asked Questions
How do I convert AAC to M4A?
Drop your .aac file into the converter above and download the M4A it produces. Everything runs in your browser — no upload, no signup, nothing sent to a server.
What's the difference between AAC and M4A?
They hold the same AAC audio, but package it differently. A raw .aac file is a bare stream with no container; M4A wraps that audio in an MP4 container with support for metadata, artwork, and reliable seeking. That container is what Apple software expects.
Will I lose quality converting AAC to M4A?
No meaningful loss — both formats use AAC audio, so this is essentially a re-wrap into the M4A container. You're not converting to a different codec, just packaging the same audio the way Apple apps expect.
Why won't my raw AAC file play in iTunes or Apple Music?
Raw .aac (ADTS) streams have no container, so iTunes, Apple Music, and the iPhone Music app often won't import them cleanly. Wrapping the audio in an M4A container fixes that, giving you proper playback, metadata, and seeking.
Is my file uploaded when converting?
No. Conversion runs entirely in your browser using FFmpeg WebAssembly, so your AAC file never leaves your device.
Is this AAC to M4A converter free?
Yes. Free users get 5 conversions per month. The output is limited to the first 10 seconds as a preview, with a 20MB input file size limit. Upgrade to Pro for unlimited, full-length conversions.