How to open .M4A files (MPEG-4 audio) on Android, Windows and Linux

A colleague sends the recording of a meeting from their iPhone and it arrives as an .m4a file. Your phone’s recorder saved a lecture as .aac. Or you have an audiobook that ends in .m4b, and none of your apps seems to know what to do with it.

All three are the same family of audio, and they play on almost anything. Folders, a free file manager for Android, Windows and Linux, opens .m4a, .aac and .m4b files in its audio player, offline and with no account.

What is an .m4a file?

An .m4a file is an MPEG-4 audio file: the same container as an MP4 video, but holding only sound. Inside, the sound is nearly always AAC (Advanced Audio Coding), a lossy codec that was designed to replace MP3 and usually sounds better at the same size. Sometimes the same .m4a extension holds Apple Lossless (ALAC) instead, which keeps every detail.

Apple’s iTunes made .m4a popular, but it’s everywhere now: the iPhone’s Voice Memos app saves .m4a, many Android voice recorders do too, and so does a lot of online audio.

Extension	What it is
.m4a	AAC (or Apple Lossless) audio in an MPEG-4 container
.aac	Raw AAC audio with no container around it, common from voice and call recorders and radio streams
.m4b	An MPEG-4 audiobook: the same format as .m4a, marked as a book and often with chapter markers

A raw .aac file has no index of where each second sits, so jumping around in a long recording can be a little less precise than in an .m4a. The sound is the same.

Two close relatives you may also see: .m4p files are songs bought from the iTunes Store before Apple dropped copy protection, and they’re locked to Apple’s software. .m4r files are iPhone ringtones, which are ordinary .m4a audio under another name.

How to open an .m4a file with Folders

On Android

1. Get Folders from the download section. The first time you open it, allow access to your files.
2. Go to where the file is: Download for attachments you saved, or your recorder’s folder (often Recordings). Typing .m4a in the search box finds every M4A in the folder you’re in and the folders inside it.
3. Tap the file. It plays in Folders’ audio player.
4. If the recording is in an email or a chat, choose Open with → Folders from that app.

On Windows and Linux

1. Install the Windows version (setup program or MSIX) or the Linux one (deb, rpm, AppImage, Flatpak, Snap or tar.gz).
2. Open the folder in Folders and double-click the file.
3. On Windows, right-click it in File Explorer and choose Open with → Folders. The installer adds Folders there for .m4a, .aac and .m4b.

What you can do with it in Folders

• Play and pause, and jump back or forward 10 seconds. Going back 10 seconds is handy when you’re writing notes from a lecture or an interview.
• Drag the seek bar to skip to the part of a long meeting you need.
• Gather all your audio into one queue with Toolbox → Music player in the side menu.
• From the file browser, rename recordings (so Recording 47.m4a becomes Budget meeting.m4a), share them, move them or compress to ZIP.

For audiobooks, be aware of what the player doesn’t do: it shows no chapter list, so an .m4b plays as one long track that you move through with the seek bar. If you listen to a lot of audiobooks, a dedicated audiobook app that shows chapters will suit you better.

Other ways to open .m4a files

• VLC plays all three on Android, Windows and Linux, and lists an audiobook’s chapters under Playback → Chapter.
• Windows’ own Media Player app plays M4A and AAC on Windows 10 and 11.
• Voice, a free, open-source audiobook player for Android, remembers your place and shows chapters in .m4b books.
• Audacity opens M4A files for editing, with its FFmpeg add-on.

Problems opening an .m4a file?

A voice recording won’t play at all. If the recorder app crashed or the phone ran out of battery while recording, the file may be missing its index, which MP4-style files usually write at the very end. Players then can’t read it. Free repair tools such as untrunc can sometimes rebuild it, using a good recording from the same app as a reference.

A song from an old iTunes library won’t play. Check the extension. An .m4p file is protected and only plays in Apple’s software with the account that bought it.

Your audiobook is .aa or .aax, not .m4b. Those are Audible’s own protected formats and need the Audible app.

An old car stereo or speaker refuses the file. Some older devices can’t play Apple Lossless, even though it uses the .m4a extension. Make an MP3 copy for that device.

Questions people ask

Can I open M4A files on Android? Yes. Folders plays all three (.m4a, .aac and .m4b): tap the file, or send it from another app with Open with → Folders.

What’s the difference between M4A and MP3? Both are compressed audio. M4A usually holds AAC, which tends to sound better than MP3 at the same size. MP3 is older and plays on more ancient hardware.

How do I convert M4A to MP3? Folders doesn’t convert audio. Use VLC’s Convert / Save option, Audacity, or the command-line tool ffmpeg (ffmpeg -i memo.m4a memo.mp3).

Why doesn’t my M4B audiobook show chapters? Folders’ audio player doesn’t read chapter markers, so the book plays as one file. VLC or an audiobook app such as Voice will show them.

More audio guides: how to open MP3 files and how to open MP4 videos. Or see all 382 file types Folders opens.