Lossless audio
Audio compression that preserves every bit of the original master, in contrast to lossy formats (MP3, AAC, Ogg) that discard inaudible data to save space.
Lossless codecs (FLAC, ALAC, WAV, AIFF) reconstruct the original PCM stream bit-perfectly. Apple Music and Tidal stream most catalog at 16-bit/44.1 kHz lossless minimum; Hi-Res lossless goes up to 24-bit/192 kHz.
Audible difference
The 16/44.1 baseline (CD quality) is widely regarded as transparent — most listeners cannot distinguish from a master in blind tests. The Hi-Res tiers are debated; reliable evidence of audibility above 16/44.1 is thin.
Bluetooth and lossless
Standard Bluetooth codecs (SBC, AAC) are lossy. Wireless lossless requires aptX Lossless + Snapdragon Sound, or LDAC at 990 kbps (near-transparent but technically lossy), or 2.4 GHz dongle systems (USB-C). Hi-Fi over Bluetooth in 2026 is finally close, not yet identical, to wired.