AAC

Advanced Audio Coding (lossy compressed).

Provides better audio quality than MP3 at similar bit rates. Uses platform-native AAC encoders/decoders (e.g., MediaCodec on Android, AudioToolbox on Apple platforms).

Read and write on Android and iOS/macOS/tvOS. JS can read after decode. JVM, native desktop, and watchOS throw UnsupportedFormatException. When writing, this produces a raw AAC stream; for an MPEG-4 container use M4A.