M4A File Format (.m4a)
An M4A file is an MPEG-4 audio container, almost always holding AAC-compressed audio and occasionally Apple Lossless (ALAC), that Apple labels with the .m4a extension to mark an MPEG-4 file as audio-only rather than video.
M4A at a glance#
| Full name | MPEG-4 Audio |
|---|---|
| File extension | .m4a |
| Category | Audio Files |
| Developer | Apple Inc. |
| MIME types | audio/mp4audio/x-m4a |
| Compression | Lossy or lossless, depending on how the file was written |
| Specification | ISO/IEC 14496-14 (MP4 file format) |
| FileFlip support | FileFlip reads and writes this format |
What a .m4a file can hold#
These are the things a M4A file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Lossless compression | Yes |
|---|---|
| Embedded metadata | Yes |
| Audio | Yes |
| Streaming | Yes |
Strengths and limitations of M4A#
What M4A does well
- Holds AAC at close to MP3 quality for less space, or Apple Lossless (ALAC) when a bit-exact copy is needed
- MP4 atom metadata embeds artist, album, artwork and track numbers in a structure iTunes and Music read natively
- Same container family as MP4 video, so it inherits mature seeking and streaming support
Where M4A falls short
- The .m4a extension only tells you the container; the audio inside could be lossy AAC or lossless ALAC with no way to tell without opening the file
- Less universally supported than MP3, particularly on older hardware and some non-Apple car stereos
- An ALAC-encoded M4A is as large as FLAC but with a much smaller ecosystem of compatible software
Use M4A for anything staying inside Apple's ecosystem, especially iTunes and Music libraries and Apple Lossless archives.
Convert M4A to MP3 for compatibility with players and devices that don't support AAC, or to FLAC if the M4A holds ALAC and you want a more widely supported lossless format.
How to open a .m4a file#
A .m4a file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts M4A into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Windows Media Player, iTunes, VLC |
| macOS | Music, QuickTime Player, VLC |
| Linux | VLC |
| iOS | Music, VLC |
| Android | VLC |
| Web | FileFlip |
M4A questions people ask#
Is M4A the same as MP3?
No, M4A and MP3 are different codecs in different containers. M4A almost always holds AAC audio, a newer codec that sounds better than MP3 at the same bit rate, wrapped in an MPEG-4 container; MP3 is both the codec and the file format at once. They aren't interchangeable without converting.
Is M4A lossy or lossless?
It depends on what's inside. Most M4A files hold AAC, which is lossy, but Apple also uses the M4A container for Apple Lossless (ALAC), which is bit-for-bit lossless. The extension alone doesn't tell you which codec a given file uses.
Does converting M4A to MP3 lose quality?
Yes, if the M4A holds AAC, since decoding AAC and re-encoding as MP3 stacks two lossy compression passes and loses more detail than either format alone. If the M4A holds Apple Lossless (ALAC), converting to MP3 is the first lossy step, and the loss comes entirely from the MP3 encoding.
What plays M4A files?
Apple's Music and QuickTime Player play M4A natively, and so do VLC, Windows Media Player 12 and later, and the built-in players on iOS and Android. Support is close to universal for AAC-based M4A files; ALAC-based ones have a smaller pool of compatible non-Apple software.
Why does iTunes use M4A instead of MP3?
Apple adopted AAC, delivered in the M4A container, because it sounds better than MP3 at the same bit rate and because the MP4 container carries richer metadata and, formerly, DRM for purchased tracks. The .m4a extension itself exists specifically to mark an MPEG-4 file as audio-only, separate from MP4 video and from the DRM-protected .m4p files iTunes once sold.
Converting M4A files#
Convert M4A to another format
Convert another format to M4A
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.