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WorldCat » WorldCat Affiliate tools » xISBN (Web service) » xISBN bookmarklet and liblookup (v2)

xISBN Bookmarklet and Library Lookup service (V2)

Got a book title from an online bookseller? Check whether your local library has it and other editions.

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Readers everywhere use (or, or other book sites) to find books of interest and then wonder if the book is available at the local library. xISBN bookmarklet makes this easy: when you have a book information page from an online bookseller displayed in your browser, you simply click on xISBN bookmarklet to automatically check your library's OPAC for books with the same ISBN and other ISBNs related to the sought-after book. This is version 2 of liblook implementation, which is integrated with Worldcat Registry and supports thousands of libraries. The version 1 of liblook implementation is still supported.

As part of integration between xISBN liblookup and Worldcat Registry, we also developed an OPAC guess system, which tries to intelligently detect OPAC vendor and its ISBN,ISSN, and OCLCNUM linking template.

Find your library

Currently this service covers thousands of libaries with good OPAC information in Worldcat Institutional Registry, find your library is easy:

Type institutional registry ID, library name, or OPAC baseurl:

Link to OPAC system by LibraryLookup service

The Library Lookup service can also be used to link to your OPAC system without invoking bookmarklet, for example:

  1. Link to Amazon
  2. Link to Princeton Library
Learn more how to use LibraryLookup service to link to your OPAC system.

Try xISBN Bookmarklets

xISBN Bookmarklet makes it easier to use LibraryLookup service by putting a Bookmarklet in your browser's Links bar.
  1. Find if your library is already covered by LibraryLookup project, if not, you can request to add your OPAC system, or update your profile in Worldcat Institutional Registry
  2. Install the Bookmarklet on your computer.
    Drag a library's link to your IE browser's links toolbar. You might try, for example, drag New York Public (Branch Libraries) to your toolbar.
  3. Next, find a book description at or (e.g. Da Vinci Code; Double Fold; Lonesome Dove)
  4. Click on your new bookmark to look it up in the library's catalog.


xISBN Bookmarklets are inspired by Jon Udell's LibraryLookup homepage, and were originally developed by Jeff Young of OCLC Research as a prototype service. We also use LibX's registry to support more libraries. The coverage of bookmarklets is signifcantly improved with the help of Insitution Registry