frequently asked questions

Show all answers  /  Print

Participation / Requirements

Do OCLC libraries have to make their holdings available via

No, OCLC libraries are not required to participate, even though the benefits of greater Web visibility for your holdings are many.

How can a library make its holdings searchable through, Google, Yahoo! and other partner sites?

  1. Contribute data about your holdings to the WorldCat database using an OCLC service, most often cataloging or batch processing, following established standards and guidelines;
  2. In the U.S. and Canada, subscribe to the WorldCat database on the FirstSearch reference service to provide your onsite and authenticated users full-featured access to WorldCat searching. For most non-North American libraries, you will need a subscription to be visible on

For complete details, see " Join WorldCat." All libraries that contribute to WorldCat earn membership in the OCLC cooperative and its associated benefits, including having a voice in future plans.

Is there a separate fee for having my holdings visible through

No, there is no separate fee for participation, although to be visible, libraries are required to use OCLC cataloging, batch processing or other services to contribute holdings and other metadata to the WorldCat database. Libraries must also maintain a subscription to WorldCat (either through FirstSearch or directly), so their onsite and remotely authenticated users have access to full-featured WorldCat searching. See " Join WorldCat" for complete details.

Why do I have to have a subscription to WorldCat on FirstSearch?

There are many costs associated with building and maintaining the systems that deliver visibility of WorldCat records on the open Web. Just as subscription access helps libraries with cost control and planning, aligning the benefits of open-Web access to WorldCat with subscription access to WorldCat on FirstSearch helps ensure a revenue level for OCLC sufficient to maintain and improve over time.

Why should my library continue to subscribe to WorldCat on FirstSearch if my users will be able to search the entire WorldCat database through

Your users—and many others in your community who are not library members—are searching the complete WorldCat database with the search box. However, after they have found an item of interest and localize their search to nearby WorldCat libraries that own the item, they only see the holdings of libraries that subscribe to FirstSearch. A FirstSearch subscription—which makes the full-featured version of WorldCat available to a library's onsite and remotely authenticated users—ensures that your library's holdings appear in results, as well as the results of Web users arriving from traffic partner sites such as Google and Yahoo!.

Since provides access to the complete WorldCat database, libraries that have subscribed to FirstSearch realize broad Web visibility for their entire physical and electronic collections, not just the popular items perhaps shown more frequently by partner sites.

Your FirstSearch subscription supports the efforts of OCLC to create broader Web-based exposure for your collections and services through a growing number of channels. People can discover your holdings through WorldCat on public views including FirstSearch, traffic partner sites such as Google and Yahoo!,, and freely distributed Web services such as the WorldCat search box, the WorldCat Search API, WorldCat Basic API and others. These channels are designed to draw in people who are not regular library users and direct them to your resources and those of all WorldCat libraries.

Why should my users or I still need to use WorldCat on FirstSearch now that the simple search box on is available?

The view of WorldCat on FirstSearch supports additional search options that some users need. Feel free to direct users to either location (FirstSearch or to conduct their searches.

If I have "block" (per-search) access to WorldCat on FirstSearch, are my WorldCat holdings visible?

No. If you currently have per-search or "block" access to WorldCat on FirstSearch, your holdings are not visible. You will need a subscription to WorldCat on FirstSearch to be visible on

Does the use of CatExpress qualify as contributing holdings to WorldCat, even though a library may not be providing all of their holdings to OCLC?

Libraries that contribute holdings through CatExpress do qualify as meeting this condition, even if this does not represent 100 percent of their cataloging activity. (The same rule applies to libraries that contribute holdings via Batch Processing, Connexion, CONTENTdm or Language Sets).

If an institution has subscription access to WorldCat by virtue of a Cataloging or WorldCat Resource Sharing authorization, does that meet the requirement for subscription access to WorldCat?

No, the institution will also need to have subscription access to (EMEA and elsewhere) or WorldCat on the FirstSearch reference service, which requires a FirstSearch authorization (North America).

In a library group setting where access to WorldCat on FirstSearch is shared and/or attached only to the main library's OCLC symbol, are the holdings of all group libraries visible through

Yes, the holdings of the entire group are visible, as long as the WorldCat subscription is identified within OCLC systems as a group authorization and group libraries are identified as affiliates of the group. The WorldCat Registry also functions as a place to designate branches and affiliations for your library that will impact the way your library appears on

Will lead to an increase in the number of resource sharing requests I receive?

Since the purpose is to promote greater library visibility to information seekers, yes, it's possible that resource sharing-related activity will increase. However, the checkpoints that your library may currently have in place (e.g., requiring authentication on your Web site) will help to control "ineligible" resource sharing requests, as will a clear, conspicuous policy statement also on your Web site. Still, your own patrons may generate more resource sharing requests due to increased awareness of your items.

WorldCat records

How many WorldCat records are searched through

All records in the WorldCat database are available to be searched on However, search results do not necessarily return all available matching items, and when a user generates a list of holdings for an item in a particular geographic area, the listings will not necessarily display all libraries in the defined region that actually have the item. This is due to the requirement that WorldCat-cataloging libraries subscribe to FirstSearch in exchange for exposure of their holdings on and partner sites such as Google and Yahoo!.

Search results may not display all matching items in the complete WorldCat database because some items, while being cataloged in WorldCat, are not actually held by any of the WorldCat libraries that presently meet the requirements for Web exposure of holdings. (In addition, some items cataloged in WorldCat may not be presently held by any WorldCat libraries at all, regardless of whether they meet the requirement.)

A user viewing the display of WorldCat libraries in his area that own an item will only see libraries that have it and meet the requirement for holdings exposure. WorldCat libraries in the area that own the item but have not subscribed to FirstSearch will not appear in the listings.

If your library contributes holdings to WorldCat but does not have visibility on, contact your OCLC representative or place an order in the OCLC Online Service Center.

How many WorldCat records are available through Google and Yahoo! Search, and how much of the records are provided to them? has a sitemap that points all search engines to more than 10.5 million records (10 million of the most widely held and the 450,000 unique items). However, search engines can also freely harvest from the entire database, especially those items on that are linked to and referenced from other sites.

Search engines index everything that is visible on the detailed record pages. If a user can see it without being authenticated, it is indexed by the search engines.

Why did OCLC assign accession numbers to the article-level records that are now included in search results?

The assignment of accession numbers facilitated the inclusion of the article-level records in search results. Article-level records were not added to the WorldCat database.


Does the search box recognize diacritics in search terms?

Yes, the search box accepts diacritical (accent) marks in provided search terms.

Is available in languages other than English?

The home page and search interface is available in seven languages: English, German, Spanish, French, Dutch, Portuguese and Chinese. Further translation of content on is forthcoming.

Note that changing the interface language does not affect the result set. For example, switching from English to French does not alter search results so that only French-language materials, or materials available from libraries in France, are displayed. The items presented to a user for a particular search remain the same regardless of the interface language.

From where does the information displayed in an individual library listing on come?

Individual library listings on display a library's name, location, "deep" links to local catalog records, and sometimes links to the library's "Ask a Librarian" virtual reference service, links to the library’s profile page on and a general information page on the library's Web site. All displayed links and information are drawn from base URLs and other information the library has entered in its institutional profile within the WorldCat Registry. (Ask a Librarian links are also automatically inserted by OCLC for libraries that participate in the QuestionPoint online reference service.) The WorldCat Registry is a free Web service that allows libraries to manage data commonly shared with vendors, funding bodies and other organizations in a single location.

Although the base URL used for deep links to an OPAC can also be managed from the FirstSearch Administrative Module (Linking tab > Web Library Catalogs page), OCLC libraries that have holdings searchable in are strongly encouraged to maintain the more complete profile provided by the WorldCat Registry. Information entered there is utilized by both the and FirstSearch interfaces.

In what order are institutions displayed in results, and how is that order determined?

The display order depends on whether the user has input a U.S. postal code or a geographic identifier associated with another country. When a user enters a U.S. postal (ZIP) code, participating libraries that hold the item are presented in order of nearest to farthest, relative to the given code. Distance determinations are based on the postal code's geographic center and the street address associated with each library's OCLC institution symbol. In some cases, this can result in out-of-state libraries preceding in-state libraries in a list of holding libraries.

The postal code entered by the user does not have to exactly match the library postal code: WorldCat uses increasingly larger concentric radiuses to find nearby libraries. These radiuses are 20 km (12 mi), 50 km (31 mi), 100 km (62 mi), "region" and "worldwide." Distance, in miles, appears for libraries out to 62 miles; beyond 62 miles, libraries are ordered alphabetically. If at least 10 libraries are not found within a given radius, WorldCat expands the search to the next area.

A user who enters only a U.S. state abbreviation (or "US" or another abbreviation for United States) sees holding libraries displayed alphabetically based on library name. A user who enters a country code for countries other than the U.S. will see libraries listed alphabetically, except for Canada, where libraries are listed by province with the provinces ordered alphabetically.

Do search results apply the FRBR concept?

Yes. WorldCat records in the search results have had a set of FRBR algorithm applied, so multiple versions of a work (e.g. different editions and formats) are rolled up under a single record. Users can click the View all editions and formats link to see other formats and versions of a work in WorldCat results. The FRBR algorithms are constantly improving in order to ensure the appropriate items are clustered together as works.

Why are there links to material purchasing at sites like

The purpose of providing opportunities to buy a work is twofold: First, to further promote libraries as a primary source of information and entertainment, enabling access to materials through a variety of channels—even retail, if a consumer sees it as the most attractive. Secondly, the links benefit libraries by capturing the transaction of a convenience-minded user who has opted to purchase materials after seeking them in the context of libraries. This may be because an item is not owned, is currently in use by another library patron, or is not physically near their location.

If a Web user adds a personal review of a book to a record, will someone else be able to edit what they have written?

No. enables users to add reviews, ratings, tags, lists and other personalized information to WorldCat records. However, fellow users are only able to see this information—not edit it. Any submitted information can only be edited by its original author.


Can a library change the deep link to its OPAC used in How quickly do changes take effect?

Yes. Change the base URL that enables "deep" links to individual local catalog records listed in the Services > Online Catalog section of your WorldCat Registry institutional profile. Information entered there is utilized by both the and FirstSearch interfaces. (The Services section of your Registry profile also lets you enter or update other links used in results, such as your IP address or address range, "Ask a Librarian" virtual reference service, OpenURL resolver for full text access, and general Web information page listing hours, location, etc.)

Changes made to your library's OPAC and service links in the WorldCat Registry should be active within 24 hours.

What is a "deep-linking URL" and how do I set it up?

A deep-linking URL is the means by which a library link within results takes a user directly to an individual item's record within your online catalog (OPAC). In order for this to occur, the "syntax" of deep links for your particular OPAC must be registered with OCLC in the Services > Online Catalog section of your WorldCat Registry institutional profile.

A deep link's syntax is the basic structure of the link, focusing on where standard identifier information about the searched item (e.g. ISBN) is embedded within the URL. A sample deep link syntax is shown below:


The "library_opac_baseURL" portion of the URL above would be replaced with the base URL for your library's OPAC (e.g. ""). In the instance shown above, the standard identifier is an ISBN, and is passed from to your OPAC with an ISBN appended after the "=" sign at the end.

If your library has not registered its deep-linking syntax for your OPAC with OCLC, users do not reach the individual item record; rather, they reach the main search page for your library's OPAC, where they must repeat their search. Please consider that the continued success of this kind of access to library content depends in part on OCLC member libraries guiding Internet searchers directly to item records.

Can authenticated users access my library's online services? users who are on an authenticated Web connection may see links to your online services in “local services” zone that is prominently featured within the detailed record. Options to view the item online, check for electronic resources or full text leads to your subscription information services that have WorldCat integration—or content available from sources such as OAIster, Hathi Trust, Internet Archive and others.

Possible links might include:

  • FirstSearch databases
  • Resource sharing
  • Document delivery
  • Full text
  • OpenURL resolvers

These links for "recognized" users reflect the services you have identified within your institutional profile in the WorldCat Registry.

Can a user link from directly to the FirstSearch service?

Yes, if the user is on an authenticated Web connection affiliated with a participating WorldCat library. They will see an area that features local services on the detailed record view that contains a link to the full-featured FirstSearch record, as well as other links to that library's fulfillment options relevant to the displayed item.

What is the URL syntax for creating direct links to WorldCat results for an item, and what can I do with it?

Anyone can create a WorldCat link for a published work—or link to keyword search results. Learn more about how to create a WorldCat link and why it’s helpful for libraries.

Comparison with FirstSearch

Why is it that the same WorldCat search performed on and then on FirstSearch produces different results?

The default order of results differs between the interface and the FirstSearch interface. Results are displayed according to relevance in, so the items most closely related to a user's search terms will appear at the top of the results. In the FirstSearch view of WorldCat, results are displayed according to the number of holdings for each item. Therefore, items that are owned by the most WorldCat libraries will appear at the top of the results.

As with major search engines, results for the same search on may vary over time, as the WorldCat database grows and OCLC improves its supporting algorithms.

What is the difference between access to databases such as the GPO, ArticleFirst, Medline and ERIC on and in FirstSearch?

The primary difference is that databases can not be searched independently from, which is designed for Web users who prefer an easy-to-use single-search interface that accepts keywords. Ranked results merge matching article citations from these databases with results for other materials cataloged in WorldCat.

On WorldCat Local and in FirstSearch, these databases will continue to be available on an individual basis with their unique indexing. This is consistent with FirstSearch's full-featured search experience, which is particularly suited to the way librarians and more experienced users approach their research.

WorldCat partner sites

Which Web sites are currently WorldCat partners?

View a complete, up-to-date list of traffic partner sites.

Can a user perform queries on Google or Yahoo! that return only links to library materials?

Yes. To limit Google or Yahoo! results to WorldCat, include as a search term, or use either site's Advanced Search and limit results to the domain.

Within Google Books, a user can select the "Find in a library" link from an individual item and get to WorldCat results.

Widgets, browser plug-ins and apps available at let anyone have WorldCat-only searching always at hand.

My library in search results

How do I know whether my holdings are being displayed?

The simplest method is to perform a keyword search for an item for which your library has claimed a holding in WorldCat. Locate the item in search results and click to the item record. If your library meets the participation requirements, it should appear in the resulting list of libraries. If it does not appear, first determine whether you have enabled deep links to your online catalog records using your institutional profile in the WorldCat Registry. (OPAC base URL is entered in the Services > Online Catalog section of the profile.)

Once enabled, it takes 24 hours before your holdings appear in results. If you still do not see your library in results after meeting the participation requirements and setting up deep links, or need help with the process, contact OCLC Support.

Why doesn't my library appear in holdings displays for items I know we have?

There could be two explanations:

  1. Your holdings may not be current for that particular item. Libraries are encouraged to make sure holdings information is current in WorldCat to ensure correct exposure through
  2. The particular item might share the same title but may exist in a different format or edition, and thus be catalogued as a separate item (e.g., a large-print or audio version of a book).

OCLC addresses the issue of duplicate records for the same title whenever it is identified, so that users are able to recognize and choose from among multiple-item records.

Why do I see a different list of libraries attached to a WorldCat record when I am in the library than when I search from my home or office?

When you search from within a library that has subscribed to public access to the WorldCat database, the IP address of the computer you use will authenticate you to see the list of all libraries with holdings attached to the record you are viewing, regardless of their subscription status. When you access from outside a subscribing library, your IP address is not recognized, so you will only see the list of subscribing libraries that hold the item.

I have just seen my library's holding symbol attached to a WorldCat record for a book we do not own. How can this happen? by default shows the holdings for all records in the FRBRized workset. The "Find a copy in the library" section displays symbols for all libraries represented for all items in the workset. To see library ownership information for a specific edition, click the "View all editions and formats" link.

You can double-check whether a library holds an exact edition from the FRBRized workset by selecting the "Just this Edition" link above the list of holding libraries.

Promoting WorldCat to users

How do I inform my library's users and our community about the availability of our holdings on

The easiest way is to add the or WorldCat Local search box to your Web site's home page. You can also use the online or print promotional tools such as table tents and posters around your library. Consider including a mention in your e-mail communications to users, and sending a press release to local media. Visit the resources page for a variety of free downloadable, customizable promotional materials and suggested social networking activities already in place (such as Facebook, Twitter, YouTube and others) to spread the word about your participation in WorldCat. Also available are Web badges, buttons and a presentation slide with talking points you can use to inform administrators, funding bodies and other high-level stakeholders about the value of for your library. news

How can I stay up-to-date about ongoing enhancements to

You can subscribe to OCLC e-mail updates. Be sure to select the "WorldCat" option as an area of interest.