What is it?

Card sorting is a technique to discover how people understand and group information. In a card sorting session, a participant will organize cards into categories that make sense to them.

Purpose of card sorting

Card sorting helps us better gauge how users structure information. Card sorting is most often used for information architecture design to structure web pages, but it shouldn’t be limited to this purpose only. For example, card sorting can be used to group relevant programs or services into categories or other similar contexts.

Planning your card sorting exercise

Participants can card sort using physical cards or online cards. Both are prepared in similar ways, where items (usually keywords, product labels, or web page titles) are put in front of users for sorting.


  • Choosing participants: The participants that you choose will have significant impact on the success of the card sorting exercise. There are multiple ways of defining your participant, depending on the purpose of your research.

Card design

  • Number of cards: It’s tempting to want to have the participants sort all of your content, however this can be tiring and overwhelming. For this reason, we suggest not to go beyond 50 cards for the participant to sort. Participants will be more likely to complete your card sorting exercise if it is more manageable.
  • Card content: Each card should represent an item that can be grouped. They can be phrases or words, ranging from very specific to more general.

Tools to use

  • In-person card sorting: There’s no specific way to prepare your cards. You can either write one item per index card or you can choose to print all the items on a piece of paper and cut them out. Make sure your cards are legible and consistent. In some cases, you may also have blank cards available for participants to suggest their own items and categories.
  • Online card sorting: There are many online tools that you can use to conduct online card sorting. Examples include Optimal Workshop and Proven by Users.

Different ways to sort

There are three common card sorting techniques. Each technique will uncover different insights on how people understand and group information.

Open card sort

Participants sort cards into categories that make the most sense to them and label the categories themselves.

When to use open card sort: Use open card sort if you want to observe how the participant would categorize the cards based on their own experience. To further understand how the participant organized the cards, you can ask the participant to talk out loud throughout the process and/or ask them why they categorized and labelled the cards the way they did.

Closed card sort

Participants sort cards into given, pre-established categories.

When to use closed card sort: Closed card sort is a great way to test an existing structure and/or category. You can also use this method if you’re adding new items to existing structure.

Hybrid card sort

Participants sort cards into given, pre-established categories, while also having the freedom to create their own categories.

When to use hybrid card sort: Use hybrid card sort if you want participants to provide feedback on existing categories while also having the option to create their own if needed.

Test setup

Moderated in-person session

Running card sorting activities in person can give you great insights. It gives you the chance to listen to the participants’ thoughts and frustrations as well as an opportunity to ask further questions.

Setting up for the session

  • Duration: The amount of time it takes for a participant to go through card sorting exercise is dependent on how complex the test set up is. You may first test internally with a colleague or friend to give you an estimate on how long the session would take, and then plan accordingly.
  • Space: Ensure that your participant has enough room to spread the cards.
  • Roles: Similar to other user research sessions, it is ideal to have a notetaker and moderator.

Facilitating the session

  • Talk out loud: Ask the participants to talk out loud so you can better understand their thoughts and frustrations.
  • Avoid leading the participant: Resist jumping right in if a category or card is unclear to the participant. This is a good insight for you that the labeling may be unclear. Let the participant do the work.

Unmoderated remote session

Online unmoderated card sorting activities can help you target more people while also save you time on setup and recruitment. You will only need to set up the card sorting exercise once and the software will be able to provide the link for you to send it out to your participants.

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