While streaming audio sites include album art in their catalogs, private collectors, especially of old vinyl, may be out of luck. Options are fewer than they used to be, given the migration to music subscriptions, but several sites still offer robust catalogs of album art that you can download for free and use to build out your collections.

Discogs is one of the largest online databases for audio. This rich audio catalog resource can be especially useful for non-mainstream recordings where software media players such as iTunes or Windows Media Player may not be able to find the correct cover art. If you have hard-to-find commercial releases, bootlegs, or white-label (promotional) material, you may be able to find the correct album art with Discogs.

The site is easy to use to find album covers not only for digital music releases, but also for older media, such as vinyl records and CDs. For digital music, you can also refine your search with a handy filter option that can display specific audio formats, such as AAC and MP3.

Musicbrainz offers a huge catalog of music information with accompanying artwork. It was originally conceived as an alternative to CDDB (short for Compact Disc Database), but has now evolved into an online encyclopedia of music that includes more information about artists and albums than simple CD metadata. For example, searching for your favorite artist will usually yield information such as all albums released by them (including compilations), audio formats, music labels, background information (relationships with others) and album art.