Google Books

Google Books (previously known as Google Book Search and Google Print) is a service from Google Inc. that searches the full text of books and magazines that Google has scanned, converted to text using optical character recognition, and stored in its digital database. The service was formerly known as Google Print when it was introduced at the Frankfurt Book Fair in October 2004. Google's Library Project, also now known as Google Book Search, was announced in December 2004.

Results from Google Books show up in both Google Web Search and the dedicated Google Books site (books.google.com). Up to three results from the Google Books index may be displayed, if relevant, above other search results in Google Web Search.

A click on a result from Google Books opens an interface in which the user may view pages from the book, if out of copyright or if the copyright owner has given permission. Books in the public domain are available in "full view" and free for download. For in-print books where permission has been granted, the number of viewable pages is limited to a "preview" set by a variety of access restrictions and security measures, some based on user-tracking. For books where permission for a "preview" has been refused, only permission for "snippets" (two to three lines of text) may be permitted, but the full text of the book is searchable on this limited basis. Where the owner of a book cannot be identified, a "snippet" view may be implemented. For other books that have neither a "full view", nor "preview", nor a "snippet" view, the text is not searchable at all, and Google Books provides no identification of content beyond the book title. For this reason, Google Books searches are an unreliable indicator of the prevalence of specific usages or terms, because many authoritative works fall into the unsearchable category.

Most scanned works are no longer in print or commercially available. For those which are, the site provides links to the website of the publisher and booksellers.

The Google Books database continues to grow. For users outside the United States, though, Google must be sure that the work in question is indeed out of copyright under local laws. According to a member of the Google Books Support Team, "Since whether a book is in the public domain can often be a tricky legal question, we err on the side of caution and display at most a few snippets until we have determined that the book has entered the public domain." Users outside the United States can however access a large number of public domain books scanned by Google using copies stored on the Internet Archive.

Many of the books are scanned using the Elphel 323 camera at a rate of 1,000 pages per hour. The scanning process is subject to errors. For example, some pages are unreadable, or upside down, or in the wrong order. It happens that some pages of one book appear interleaved with those of another, or an entire book may be attributed to the wrong title altogether. Book information such as authors, publishers, dates and so on, may be incorrect or abbreviated incoherently. Very commonly, the list of chapter headings and/or the book index is only partially presented. Although at one time Google provided feedback links to report these problems, the mechanisms for readers to provide this feedback have become more and more curtailed as time goes on.

The initiative has been hailed for its potential to offer unprecedented access to what may become the largest online body of human knowledge and promoting the democratization of knowledge, but it has also been criticized for potential copyright violations.

As of March 2012, the number of scanned books was over 20 million, but the scanning process has slowed down. Google estimated in 2010 that there were about 130 million unique books in the world, and stated that it intended to scan all of them by the end of the decade.