What is HD Internet Radio?

“HD radio” on the internet means bit-perfect audio with codecs like FLAC or ALAC.

Standard web streams use compressed MP3/AAC 128–192 kbps. CD quality is 16-bit / 44.1 kHz, around 1.4 Mbit/s in raw PCM. Lossless FLAC usually sits at 700–1100 kbps while preserving every sample of the original signal.

The result: sound that can match local CD playback — as long as the mastering is good and your playback chain is transparent.