--- title: "Card Sorting" url: "https://www.insideuxdesign.com/en/glossar/card-sorting" language: "en" description: "What is card sorting? A plain-language guide with an example and tips. Learn how to find out how people group content and build menus they understand." published: "2026-10-14T09:50:31+02:00" updated: "2026-10-14T13:00:51+02:00" --- # Card Sorting Card sorting is a research method in which people sort terms written on cards into groups. It shows you how they mentally organize content, so you can plan navigation that makes sense to them. - **Buchstabe:** C UX glossary # Card Sorting Card sorting is a research method in which people sort terms written on cards into groups. It shows you how they mentally organize content, so you can plan navigation that makes sense to them. Imagine a local sports club rebuilding its website. The board has spent weeks debating whether “Fees” belongs under “Membership” or “Services”, and whether parents would look for training times under “Teams” or “Calendar”. Everyone is sure they’re right. Instead of arguing any longer, the team asks the people who will actually use the site, with a stack of cards. ## Explained simply Card sorting is a research method in which participants sort terms written on cards into groups that make sense to them. Each card stands for a piece of content, such as a page or a feature. You know the principle from organizing a kitchen: some people sort by type of utensil, others by what they need for baking or cooking. Card sorting shows you the logic people carry in their heads, in other words their [mental model](https://www.insideuxdesign.com/en/glossar/mental-model). The results help you build an [information architecture](https://www.insideuxdesign.com/en/glossar/information-architecture): the structure and labeling of content, shaped by what users expect rather than by the company’s org chart. ## Open, closed or hybrid In **open** card sorting, participants create their own groups and name them. This is the most common variant and works well when you don’t have a structure yet. In **closed** card sorting, you provide the categories and participants only assign the cards. To validate a finished structure, though, the Nielsen Norman Group generally recommends [tree testing](https://www.insideuxdesign.com/en/glossar/tree-testing) instead. The **hybrid** form mixes both: some categories are given, and participants can add their own. You can also run a card sort moderated or unmoderated. In a moderated session, someone sits in and asks why a card ends up in a particular group. Unmoderated sessions run through an online tool like [Optimal Workshop](https://www.insideuxdesign.com/en/ressourcen/optimal-workshop), which gives you more data for quantitative analysis. ## An example Back to the sports club. Before, the site mirrors the club’s committees: “Board”, “Office”, “Youth Committee”. Anyone looking for under-10 training times has to click through three menus. An open card sort with 15 members and parents reveals a clear pattern: almost everyone puts training times, the gym schedule and the team contact on one pile and calls it something like “My team”. After the redesign, each team has its own page with exactly that content, and the committees move to an “About the club” section. ## Common misconceptions Card sorting gives you ideas for a structure, not a finished navigation. The group names participants come up with are suggestions, not final menu labels. And because different people often group the same content differently, you still need your own judgment and a second test that checks the structure. You can read more in [Card Sorting Basics: Efficient Information Architecture for Beginners](https://www.insideuxdesign.com/en/blog/card-sorting-basics-information-architecture-for-beginners). ## In practice - **Keep the deck manageable.** The Nielsen Norman Group recommends 30 to 50 cards. With more, participants get tired and dump lots of cards into a big “Miscellaneous” pile. - **Recruit enough participants.** For qualitative insights, at least 15 people is a sensible minimum. For solid quantitative results, plan for 30 to 50. - **Avoid giveaway words.** When several cards share the same word, people tend to group by that word instead of by meaning. Word your cards differently and try them out with one or two people first. ## Related terms [Information Architecture](https://www.insideuxdesign.com/en/glossar/information-architecture), [Tree Testing](https://www.insideuxdesign.com/en/glossar/tree-testing), [Mental Model](https://www.insideuxdesign.com/en/glossar/mental-model), [User Research](https://www.insideuxdesign.com/en/glossar/user-research) ## Sources - [Samhita Tankala, Katie Sherwin: Card Sorting: Uncover Users’ Mental Models for Better Information Architecture. Nielsen Norman Group, 2024](https://www.nngroup.com/articles/card-sorting-definition/) - [Jakob Nielsen: Card Sorting: How Many Users to Test. Nielsen Norman Group, 2004](https://www.nngroup.com/articles/card-sorting-how-many-users-to-test/) - [Samhita Tankala: Card Sorting vs. Tree Testing. Nielsen Norman Group, 2024](https://www.nngroup.com/articles/card-sorting-tree-testing-differences/) ## More terms [ ### A/B Testing An A/B test is an experiment that shows two versions of a page or element at the same time to randomly split groups of visitors. It lets you decide with real data which version works better. ](https://www.insideuxdesign.com/en/glossar/a-b-testing) [ ### ARIA ARIA is a W3C standard that adds roles, states and properties to HTML. It tells screen readers what an element is and how it currently behaves. ](https://www.insideuxdesign.com/en/glossar/aria) [ ### Accessibility Accessibility means designing websites, apps and digital documents so that everyone can use them, including people with visual, hearing, motor or cognitive disabilities. ](https://www.insideuxdesign.com/en/glossar/accessibility) [ ### Affordance An affordance describes what action an object makes possible and whether people can recognize it: a button invites you to press it, a handle invites you to pull. ](https://www.insideuxdesign.com/en/glossar/affordance) [ ### Alt Text Alt text is a short text version of an image, stored in the HTML alt attribute. Screen readers read it aloud so people who can’t see the image get the same information. ](https://www.insideuxdesign.com/en/glossar/alt-text) [ ### Atomic Design Atomic Design is a method for building user interfaces from small, reusable building blocks, from single elements like buttons all the way up to complete pages. ](https://www.insideuxdesign.com/en/glossar/atomic-design) [ ### BFSG The BFSG, Germany’s Accessibility Strengthening Act, has required many companies since 28 June 2025 to make certain products and digital services, such as online shops, accessible. ](https://www.insideuxdesign.com/en/glossar/bfsg) [ ### Cognitive Load Cognitive load is the mental effort it takes to understand and use an interface. The less unnecessary thinking a design demands, the easier the actual task becomes. ](https://www.insideuxdesign.com/en/glossar/cognitive-load) [ ### Color Vision Deficiency A color vision deficiency means someone has a harder time telling certain colors apart than most people. The most common type is red-green deficiency. ](https://www.insideuxdesign.com/en/glossar/color-vision-deficiency) [ ### Contextual Inquiry Contextual inquiry is a research method where you observe and interview people in their real work environment. It shows you how they actually get tasks done, not just how they describe it. ](https://www.insideuxdesign.com/en/glossar/contextual-inquiry) [ ### Contrast Ratio The contrast ratio describes how much two colors differ in brightness, such as text and background. WCAG requires at least 4.5:1 for normal text. ](https://www.insideuxdesign.com/en/glossar/contrast-ratio) [ ### Conversion A conversion is a desired action on a website or in an app, such as a purchase or a signup. The conversion rate shows what share of visits leads to one. ](https://www.insideuxdesign.com/en/glossar/conversion)