Question 1

What's the difference between .aac and .m4a?

Accepted Answer

Both hold AAC audio. A .aac file is a raw stream of AAC frames (called ADTS) with almost no room for tags, while a .m4a file wraps the same audio in an MPEG-4 container with tags and cover art. This converter reads both.

Question 2

Why convert AAC to MP3 if AAC is the better codec?

Accepted Answer

For compatibility. Some car stereos, older MP3 players, DJ apps and upload forms only accept MP3. AAC does sound better at the same bitrate, so converting is about where the file has to play, not about quality.

Question 3

What MP3 bitrate matches my AAC file?

Accepted Answer

Pick a step above the AAC bitrate. A 128 kbps AAC holds up well as a 192 kbps MP3, and a 256 kbps AAC as a 320 kbps MP3. Going higher than that only makes the file bigger.

Question 4

Where do .aac files come from?

Accepted Answer

Some call recorders, dashcams, radio stream rippers and older Android voice recorders save raw .aac files. They're also a common result of extracting audio from a video without converting it.

Question 5

Can it read HE-AAC files?

Accepted Answer

Usually, yes. Chrome, Edge and Safari decode both standard AAC-LC and the HE-AAC used for low-bitrate streams and radio. Support in Firefox depends on your operating system.

Question 6

Are my AAC files uploaded?

Accepted Answer

No. The audio is decoded and encoded to MP3 on your device, so nothing is sent to a server.

AAC to MP3 Converter

How it works

FAQ

More audio tools