LibraryThing is a social cataloging web application for storing and sharing book catalogs and various types of book metadata. It is used by authors, individuals, libraries, and publishers.

Type of site
Catalog and community
Created byTim Spalding
LaunchedAugust 29, 2005; 18 years ago (2005-08-29)
Current statusActive

Based in Portland, Maine,[1] LibraryThing was developed by Tim Spalding and went live on August 29, 2005, on a freemium subscriber business model, because "it was important to have customers, not an 'audience' we sell to advertisers." They focused instead on making a series of products for academic libraries. Motivated by the cataloguing opportunities and financial challenges presented by the COVID-19 pandemic, the service went "free to all" on March 8, 2020, while maintaining a promise never to use advertising on registered users.[2] As of February 2021, it has 2,600,000 users and more than 155 million books catalogued,[3] drawing data from Amazon and from thousands of libraries that use the Z39.50 cataloguing protocol.



The primary feature of LibraryThing (LT) is the cataloging of books, movies, music and other media by importing data from libraries through Z39.50 connections and from six stores. Library sources supply Dublin Core and MARC records to LT; users can import information from over 2000 libraries, including the British Library, Canadian National Catalogue, Library of Congress, National Library of Australia, and Yale University.[4] Should a record not be available from any of these sources, it is also possible to input the book information manually via a blank form.[5]

Each work may comprise different editions, translations, printings, audio versions, etc. Members are encouraged to add publicly visible reviews, descriptions, Common Knowledge and other information about a work; ratings, collections and tags help categorization. Discussion in the forums is also encouraged.

Items are classified using the Melvil Decimal System, based on the out-of-copyright 1922 edition of the Dewey Decimal Classification with modifications for standard spelling of division names (as opposed to the original names, which were spelled in accordance with Dewey's advocated spelling reforms), and modernised terminology.[6]

Social features


LibraryThing's social features have been compared to bookmark manager[7] and the collaborative music service[8] Similar book cataloging sites include aNobii, BookLikes, Goodreads, Libib, Shelfari (now merged with Goodreads), and weRead.[9]



In 2016, LibraryThing launched TinyCat, an OPAC designed for the cataloging and circulation of libraries of up to 20,000 items.[10] TinyCat is marketed towards small independent libraries, such as schools, community centers, religious institutions, and academic departments, as well as individuals.[11]



LibraryThing is majority owned by founder Tim Spalding.[12] Online bookseller AbeBooks bought a 40% share in LibraryThing in May 2006 for an undisclosed sum. AbeBooks became a subsidiary of Amazon in 2008.[13] In January 2009, Cambridge Information Group acquired a minority stake in LibraryThing, and their subsidiary Bowker became the official distributor to libraries.[12]



At the end of June 2006, LibraryThing was subject to the Slashdot effect from a Wall Street Journal article.[14] The site's developers added servers to compensate for the increased traffic. In December of the same year, the site received yet more attention from Slashdot over its UnSuggester feature, which draws suggestions from books least likely to appear in the same catalog as a given book.[15]

See also



  1. ^ "LibraryThing – Send us money".
  2. ^ "LibraryThing Is Now Free to All « The LibraryThing Blog". Retrieved March 30, 2022.
  3. ^ "Zeitgeist Overview". LibraryThing. Retrieved February 8, 2021.
  4. ^ "Add books to your library". Retrieved June 3, 2008.
  5. ^ "Manual Entry". Retrieved October 13, 2010.
  6. ^ Spalding, Tim (August 19, 2010). "Introducing the "Melvil Decimal System"". LibraryThing. Retrieved July 23, 2016.
  7. ^ Regan, Jim (November 9, 2005). "Do your own LibraryThing". Christian Science Monitor. Retrieved March 13, 2007.
  8. ^ Bain, Alistair (April 28, 2007). "LibraryThing". Desert of Zin. Archived from the original on November 3, 2011. Retrieved June 20, 2007.
  9. ^ Woodroof, Martha (March 20, 2008). "Web Sites Let Bibliophiles Share Books Virtually". NPR. Retrieved May 14, 2009.
  10. ^ "Introducing TinyCat: The OPAC for Tiny Libraries". LibraryThing Blog. April 5, 2016. Retrieved June 26, 2016.
  11. ^ Klein, Loren (August 19, 2015). "New LibraryThing OPAC, TinyCat, Announced". Public Libraries Online. Retrieved June 26, 2016.
  12. ^ a b "CIG Acquires Minority Stake in LibraryThing; Bowker to Distribute to Libraries". Archived from the original on August 5, 2009. Retrieved April 3, 2013.
  13. ^ Davies, Richard (May 16, 2006). " Acquires Major Stake In – A Social Networking Site For Bibliophiles". Archived from the original on August 26, 2016.
  14. ^ Rutkoff, Aaron (June 27, 2006). "Social Networking for Bookworms". Wall Street Journal. Retrieved December 15, 2006.
  15. ^ "Unsuggester: Finding the Book You'll Never Want". Slashdot. December 4, 2006. Retrieved December 15, 2006.

Further reading