WorldCat is the world's largest bibliographic database, containing catalogs of thousands of online Computer Library Center members libraries. WorldCat is looked after by librarians. WorldCat itself is not Online Computer Library Center ( OCLC ) service.

WorldCat was founded as an "online shared cataloging " 1971.


Critics in the old stocks that provenance research are not possible, since, unlike in the composite of Research Libraries ( RLG) local observations ( notes) are not visible.

Open WorldCat

The open-access Open WorldCat is facing almost 300 million items in 470 languages. These records contain nearly 1.9 billion holding records. Added every year more than two million records.

Limitations compared to WorldCat:

  • Compared to the Open WorldCat WorldCat is a simplified search interface to facilitate for the less experienced user searching.
  • The data of the Open WorldCat are part of the " First Search " range of OCLC. " First Search " provides a link between different OCLC databases and is chargeable. The use of Open WorldCat is not bound to " First Search ".