Online Public Access Catalog (OPAC)

What is an Online Public Access Catalog (OPAC)?

An Online Public Access Catalog (OPAC) is a digital tool that libraries use to help people find and locate books, articles, and other materials within their collections. This system has changed the way people find information in libraries, moving from the old card catalog system to a new online search system.


OPACs are easy to use, offering different ways to search, like by author, title, subject, or keywords, making it quick to find what you need.

Techopedia Explains the OPAC Meaning

Techopedia Explains the OPAC Meaning

OPACs do more than just help people find what they’re looking for in the library; they also give detailed information about each item, such as if it’s available, where it’s located in the library, and its call number.

Some more advanced OPAC systems even let people reserve items, get direct access to online materials, and see their loan history.

The History of OPACs

Online Public Access Catalogs have significantly impacted archival research methodologies.

OPAC library systems started in the 1960s and 1970s with simple systems mainly used by universities and research institutions. These early versions were a big change from the old card catalogs and set the stage for better systems.

By the late 1970s and early 1980s, OPACs became easier to use, and more people could access them. Libraries began using commercial systems to manage their collections digitally, moving away from the traditional card catalogs. This allowed people to search for books and other items on computers.

From the 1990s to now, OPACs have gotten even better, thanks to the Internet. They now have advanced search options, can be accessed from anywhere, and work with online libraries and resources.

This growth shows how libraries are moving towards managing information digitally and making sure everyone can access their collections easily. Today, OPAC library systems stand as a testament to how technology can open up access to knowledge for everyone.

How OPAC Works

Understanding the OPAC meaning helps in appreciating how it acts as a digital bridge, linking users to a library’s collection via an online search system.

This means the following features and benefits:

  • Digital Access:
    • Allows online searches for library materials.
  • Search Capabilities:
    • Allows searches by author, title, subject, or keywords.
    • More advanced OPAC library systems offer Boolean and keyword searches for precision.
  • User Interaction:
    • User interaction in cataloged research is streamlined.
    • Displays detailed information, including availability and location of materials.
    • Offers direct access to online materials.
    • Users can reserve items that are currently checked out.
    • Sometimes even allows users to leave reviews or ratings.
  • Library Management:
    • Makes it easy for librarians to handle the collection.
    • Facilitates adding new items and updating their status.
    • Provides insights into how often materials are checked out to improve services.
  • Technical Infrastructure:
    • OPAC library systems use robust database management systems (DBMS) for efficiency.
    • Integrates with the library’s main management system for seamless and real-time information.

Types of OPAC

Types of OPAC

Standalone OPACs
  • Early version of library catalogs.
  • Used on dedicated computers inside the library.
  • Allow searching the catalog from specific locations within the library.
  • Less common now but important for the development of newer systems.
Web-Based OPACs
  • Web-based OPACs epitomize the online public access catalog website by offering remote access.
  • Enable accessing the library catalog over the Internet.
  • Can be used from anywhere with Internet access.
  • Features include easy-to-use interfaces and advanced search options.
  • Often integrated with other library services for a better user experience.
Integrated OPACs
  • Part of a larger library management system.
  • Offer a unified experience for users and library staff.
  • Combine catalog searching with other functions like borrowing and managing resources.
  • Aim to make library operations smoother and improve access to various resources.

Online Public Access Catalog Software

OPAC Software Type Key Features
Koha Open source
  • Leading system for managing libraries.
  • Allows for easy search and management of user accounts.
  • Links to online resources.
Evergreen Open source
  • Designed for scalability, ideal for consortia and large libraries.
  • Robust organization and lending features.
  • User-friendly with ways to make it your own.
SirsiDynix’s Symphony Commercial
  • Complete system for bigger libraries, with powerful tools for searching and customization.
  • Integrates smoothly with electronic resource management.
  • Suits academic and large libraries.
Ex Libris’s Alma Commercial
  • Integrates various library tasks into one system.
  • Powerful search and customization functions.
  • Focused on the needs of universities and big libraries.
OCLC’s WorldCat Discovery Global cooperative
  • An online public access catalog website that connects users to a worldwide catalog of library collections.
  • Makes it easy to discover library materials in different places.

Uses of OPAC

The Online Public Access Catalog (OPAC) is a crucial tool that serves multiple purposes within the library ecosystem, enhancing both user experience and library management.

Educational Support and ResearchCommunity EngagementPersonalized User ExperiencesDigital and Multimedia ResourcesProfessional and Lifelong Learning
  • Helping with Academic Research: OPAC library systems are indispensable tools for cataloged research in academic settings. They make it easier to find all sorts of study materials, like articles, papers, and books needed for research.
  • Resources for Teaching: Teachers can use OPACs to get materials that help with making lessons and teaching students.
  • Events and Workshops: The OPAC definition expands to include its rule in community engagement since it shows what’s happening at the library. OPACs often advertise special events or learning workshops, and let people sign up for them.
  • Discovering Local History: OPACs facilitate archival research by providing access to local history collections.
  • Book Suggestions and Reviews: OPACs can suggest books you might like based on what you’ve read before or let you see what others think about a book.
  • For Everyone: OPACs have features to help people no matter what language they speak or if they need special accessibility options.
  • E-Books and More: Besides books, OPACs give you access to a huge range of digital items like e-books, online articles, and more.
  • Watching and Listening: Find links to watch documentaries or listen to music right from the OPAC.
  • Growing Your Career: OPACs offer resources for learning new job skills, taking courses, or even getting certificates.
  • Learning for Fun or Interest: Whether you want to pick up a new hobby, learn a language, or explore a topic just for fun, OPACs have resources for that too.

Pros and Cons of OPACs


  • Allow you to explore the library’s collection and reserve items online anytime, anywhere
  • Enable quick discovery of books and topics of interest via keyword search
  • Provide tools for account management, including renewing books, tracking borrowed items, and placing holds on desired items
  • Reduce the necessity for physical catalogs and lessen the demand on library staff’s time
  • Offer access to e-books and other online resources, expanding beyond physical books


  • Can present challenges due to compatibility or Internet issues
  • Risk over-reliance on technology, particularly during system crashes or among those with limited digital literacy
  • Make searching for specific items challenging due to the abundance of materials
  • Decrease personal interaction with library staff through reliance on digital catalogs
  • Raise concerns about data privacy regarding digitized library records and online activities

The Bottom Line

In summary, the development of the OPAC has played a crucial role in modern libraries. It has changed the way people use libraries, helping with archival research and improving cataloged research.

Learning the OPAC meaning shows us its wide range of uses, from supporting education to engaging communities and providing access to digital resources. The OPAC library system has made it easier for everyone to find information, becoming a key tool for those seeking knowledge.

As libraries keep evolving, the significance of OPACs in providing access, improving efficiency, and empowering users is very important, marking the start of a new era in library services.


What is the online public access catalog in simple terms?

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What are the 3 types of OPAC?

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Maria Webb
Technology Journalist

Maria is a technology journalist with over five years of experience with a deep interest in AI and machine learning. She excels in data-driven journalism, making complex topics both accessible and engaging for her audience. Her work is prominently featured on Techopedia, Business2Community, and Eurostat, where she provided creative technical writing. She holds a Bachelor of Arts Honours in English and a Master of Science in Strategic Management and Digital Marketing from the University of Malta. Maria's background includes journalism for, covering a range of topics from local events to international tech trends.