MP3 to M4A Converter

Converting MP3 to M4A re-encodes through the AAC codec and wraps it in an MPEG-4 container. The result is typically 30% smaller than the MP3 at matching perceived quality, with proper iTunes-style metadata, embedded artwork, and chapter support baked in.

audio_file

Drag & drop audio files here, or browse

Drop your MP3 files here

What changes when you convert MP3 to M4A

This is a lossy-to-lossy transcode, so expect a small, usually inaudible quality drop. Matching or exceeding the MP3's bitrate keeps the loss negligible. In exchange you get Apple-native playback, better tagging, and smaller files.

When to use this conversion

  • Importing music into iTunes or Apple Music libraries that handle M4A far more cleanly than MP3
  • Building audiobooks where M4A supports chapter markers and per-chapter metadata
  • Syncing to an iPhone, iPad, or Apple Watch without iTunes transcoding on the way in
  • Consolidating a mixed MP3/M4A library to a single container format

Where the output plays

M4A plays on all Apple devices, Windows (via iTunes, Groove, VLC), Android (native), and every modern browser. Some older car stereos and cheap MP3 players won't recognize M4A; those remain MP3-only territory.

About these formats

MP3 (MPEG-1 Audio Layer III)

MP3 is the most widely supported lossy audio format. Encoded in 1993 and still the default on countless devices, it trades some fidelity for dramatically smaller files. At 192 kbps most listeners cannot distinguish it from the source. Anything that plays audio will play MP3.

M4A (MPEG-4 Audio)

M4A is an MPEG-4 container that almost always holds AAC audio (though it can hold ALAC too). The payload is identical to what's inside an .aac file; the difference is that M4A carries proper tags, chapter markers, and cover art. iTunes, Apple Music, and iOS write M4A by default.

How It Works

  1. Add your MP3 files Drag MP3 files onto the page, or click to pick them from your file browser. Batch uploads are fine.
  2. Choose M4A settings Pick bitrate or quality level for the M4A output. Defaults match common target use cases.
  3. Convert in your browser FFmpeg runs locally via WebAssembly. Nothing uploads. Progress shows per file so you know exactly what's happening.
  4. Download M4A files Grab each converted file individually, or download the whole batch as a single ZIP.

Features

Supported Formats

FAQ

Is M4A the same as AAC?

The audio inside is AAC. M4A is the container, an MPEG-4 wrapper that adds tag, artwork, and chapter support. Playback quality is identical to a raw .aac stream.

Will M4A play outside Apple devices?

Yes. Android, Windows, and modern browsers all handle M4A natively. The edge cases are older cars, dash cams, and cheap MP3 players that were built before AAC support was common.

What is MP3 (MPEG-1 Audio Layer III)?

MP3 is the most widely supported lossy audio format. Encoded in 1993 and still the default on countless devices, it trades some fidelity for dramatically smaller files. At 192 kbps most listeners cannot distinguish it from the source. Anything that plays audio will play MP3.

What is M4A (MPEG-4 Audio)?

M4A is an MPEG-4 container that almost always holds AAC audio (though it can hold ALAC too). The payload is identical to what's inside an .aac file; the difference is that M4A carries proper tags, chapter markers, and cover art. iTunes, Apple Music, and iOS write M4A by default.

Are my files private?

Yes. The converter runs entirely in your browser using FFmpeg compiled to WebAssembly. Your audio files are never uploaded, never sent to a server, and never leave your device.

Is there a file size limit?

There's no hard limit, but because everything runs in your browser you're bounded by available memory. Files over about 2 GB total can get slow or hit browser memory limits. Process in smaller batches if you run into issues.