Lossless audio refers to digital audio compression formats that reduce file size without discarding any audio data. Unlike lossy formats (MP3, AAC, Ogg Vorbis) which permanently remove sounds deemed less perceptible to save space, lossless formats (FLAC, ALAC, WAV, AIFF) preserve every bit of the original recording. When decoded, a lossless file is bit-for-bit identical to the source.
The most popular lossless formats are FLAC (Free Lossless Audio Codec) — open-source and widely supported, ALAC (Apple Lossless Audio Codec) — Apple's proprietary format for iTunes and iOS, WAV (Waveform Audio) — uncompressed audio, and AIFF (Audio Interchange File Format) — Apple's uncompressed format. FLAC is the most versatile choice, reducing file sizes by 40-60% compared to WAV while maintaining identical audio quality.
For vinyl and CD collectors, lossless audio bridges physical and digital. You can rip your CDs to FLAC files and serve them through a personal music server (like Jellyfin, Navidrome, or Plex) for lossless streaming anywhere — without monthly subscription fees. This is the "own your music" philosophy taken to its logical conclusion: physical purchase → lossless rip → personal cloud library. You get the ownership of physical media with the convenience of streaming.
Apple Music and Amazon Music now offer lossless streaming (up to 24-bit/192kHz), but Spotify still streams only lossy audio as of 2025.