On any item page, look for the download box on the right. You will typically see options for VBR MP3 and FLAC.

Thousands of independent record labels upload their entire catalogs to the Archive. This is a goldmine for experimental, electronic, and indie music that may not be available on mainstream streaming platforms like Spotify.

"Preserving Musical Heritage: An Analysis of Internet Archive's FLAC Music Collection and its Implications for Music Preservation and Accessibility"

Not all audio on the site is FLAC. Much of it is MP3 or OGG Vorbis. To ensure you are downloading lossless files, use the advanced search or look for the file format list on an item's page.