.aacaudio
AAC
Advanced Audio Coding
MIME type: audio/aac
AAC is a lossy audio compression format designed as the successor to MP3. It delivers better sound quality than MP3 at the same bitrate and is the default audio format for Apple devices, YouTube, and most streaming platforms.
Advantages
- +Better quality than MP3 at same bitrate
- +Default format for Apple/iTunes
- +Used by YouTube, Spotify, Netflix
- +Efficient compression
Limitations
- -Lossy — some quality loss
- -Less universal than MP3 on older devices
- -Patent-encumbered (unlike MP3 since 2017)
- -Multiple profiles can cause compatibility issues
Common Use Cases
Music streamingPodcastsVideo soundtracksMobile audio
Technical Details
AAC uses a modified DCT with temporal noise shaping and backward prediction. It supports sample rates from 8 kHz to 96 kHz and up to 48 channels. Common profiles: AAC-LC (Low Complexity, most common), HE-AAC (High Efficiency for low bitrates), and HE-AAC v2.
Frequently Asked Questions
AAC vs MP3 — which is better?
AAC delivers better audio quality than MP3 at the same bitrate. At 128kbps, AAC sounds roughly equivalent to MP3 at 160kbps. For modern use, AAC is the better choice.