AAC vs MP3

Yes, particularly at lower bitrates. AAC at 128 kbps typically sounds comparable to MP3 at 192 kbps. At higher bitrates like 256–320 kbps, both formats sound very similar and the difference is minor.

Apple Music streams at 256 kbps AAC. Apple uses AAC as its default format across iTunes, Apple Music, and all Apple devices. AAC is essentially the successor to MP3 in the Apple ecosystem.

Most modern devices can play AAC, but some older MP3 players and legacy hardware only support MP3. If you're unsure about the target device, MP3 is the safer choice for universal playback.

No — converting between lossy formats causes generation loss, making quality worse. Keep your existing MP3 files as is. Only convert lossless sources (like FLAC or WAV) to AAC for distribution.

AAC is covered by patents held by the MPEG licensing authorities. While playback is generally free for consumers, software developers who distribute AAC encoders may need licenses. MP3 patents expired in 2017, making it completely royalty-free.