WorldCat

The union catalog of the world's libraries — find who holds a book or item, and where.

Tier 2

At a Glance

Publisher
OCLC (a nonprofit library cooperative)
Coverage

540M+ bibliographic records representing billions of physical and digital holdings from tens of thousands of libraries worldwide (verify current counts).

Access

Free public search at worldcat.org; deeper discovery and interlibrary-loan features through member libraries.

Free alternative
It is free; Google Books and library OPACs for specific holdings.
Regional

Global, with deepest coverage of North American and European library holdings.

Our Take

WorldCat is not a full-text database but a discovery layer — the shared catalog that tells you which libraries hold a given book, journal, thesis, or recording, which makes it the fastest way to locate a physical item or route an interlibrary-loan request. For anyone chasing a hard-to-find monograph or older material, it is indispensable, and the free public search is genuinely useful. The limits are that it is holdings, not content: it points you to items rather than delivering them, and record quality varies by contributing library. Use it to find and request what exists; get the text through the holding library or a full-text source.

Power Tips

  • Search here first to find the nearest library holding a scarce book, then place an interlibrary-loan request through your own library.
  • Use it to confirm a citation’s edition and publication details before ordering.
  • Do not expect full text — WorldCat locates items, it does not deliver them.

Alternatives & Complements

Google Books, Library of Congress catalog, HathiTrust, Internet Archive

Figures last verified: June 15, 2026