Discover how users naturally organize your content
Run an open card sort in minutes. Participants create their own categories — revealing the mental models that should drive your information architecture. Free forever.
No credit card required · Unlimited free studies · Setup in under 5 minutes
What is Open Card Sorting?
Let users show you how they think
In an open card sort, participants receive a set of content items (cards) and organize them into groups that make sense to them — naming each group themselves. There are no predefined categories. This reveals how your users naturally think about your content, what language they use, and what groupings feel intuitive. It's the ideal starting point for building an information architecture grounded in real user mental models.
Category Agreement
How often do participants group the same cards together? High agreement = strong natural clusters.
Common Groupings
What category structures appear most frequently? These become your IA blueprint.
Outlier Items
Which cards do participants struggle to categorize? These reveal content that needs rethinking.
Features
Everything you need to run an open card sort
Drag-and-Drop Sorting
Participants drag cards into groups they create themselves. Intuitive interface with high completion rates.
Custom Category Creation
Participants name their own categories — revealing the exact language your users think in.
Automated Analysis
Get similarity matrices, dendrograms, and category frequency charts as soon as responses come in.
Built-in Recruitment
Recruit verified participants (~$3.50/response) or share your card sort link anywhere. $40 free credit included.
AI Test Responses
Preview your card sort with AI-generated responses before recruiting real participants. Catch issues early.
No-Friction Participation
Participants open a link and start — no signup, no install. Clean drag-and-drop experience on any device.
How It Works
From cards to categories in three steps
Add your cards
Enter the content items you want participants to organize. Paste from a spreadsheet or type them manually. It takes about 5 minutes.
Collect responses
Share your card sort link or recruit participants via built-in recruitment. Participants drag cards into groups they create and name themselves.
Discover patterns
See which cards are grouped together most often, what category names participants use, and which items are outliers. Use these patterns to build your IA.
Results Dashboard
See the patterns your users reveal
Your open card sort results update in real-time. ValidateThat automatically identifies the strongest groupings, most popular category labels, and outlier items — so you can build an IA grounded in real user mental models.
- Similarity matrix showing card-pairing frequency
- Dendrogram visualizing natural clusters
- Category frequency and label analysis
- CSV export for deeper analysis (Pro)
Open → Closed → Tree Test
Open card sorting is where great IA begins
Open card sorts reveal how users think about your content. Follow up with a closed card sort to validate your categories, then a tree test to confirm users can find things. ValidateThat lets you run all three in one project.
- Open, closed card sorts, and tree tests in one project
- Use open sort clusters as your IA blueprint
- Validate with closed sort and tree test
- Share findings in a stakeholder report
Comparison
Open card sorting tools compared
Stop guessing how users think. Ask them.
Create an open card sort in 5 minutes. Get results in hours. Build an information architecture grounded in real user mental models.
No credit card · No contracts · Cancel anytime
Use Cases
When to run an open card sort
Building IA from scratch
Starting a new product or website? An open card sort reveals how your users think about your content before you commit to a structure.
Early-stage IA research
Exploring a new content domain or audience? Open card sorts surface the mental models you need to understand before designing navigation.
Content strategy planning
Figuring out how to organize a large content library? Let users show you the natural groupings rather than imposing your own assumptions.
Understanding user language
Open card sorts reveal the exact words users use for categories — not internal jargon. Use their language for navigation labels.
Comparing audience segments
Run the same open card sort with different user groups to see if developers, marketers, and executives organize content differently.
Major site redesign
Before redesigning your navigation, run an open card sort to challenge your existing assumptions about how content should be organized.
FAQ
Frequently asked questions
Your users already know how to organize your content. Let them show you.
Create a free open card sort and discover the mental models that should drive your information architecture.
No credit card · No contracts · Cancel anytime