You will need

Design A and Design B


approximately 24 hours


at least 50 users


2 – depending on what tools you use

Use when...

  • choosing between two designs
  • you want to find out if the new version works better than the original one
  • you know what goals the designs should achieve

Do not use when...

  • you have only one version (try User Testing instead)
  • you have many versions to choose from
  • you cannot say who is your user going to be


  1. Design two new forms of the service or compare the already existing one with the newly designed. You can also, for example, examine information leaflet or website of an institution.
  2. The testing should be conducted together with users who are going to actually use the product or service. Do not leave the selection and addressing of the tester for the last minute.
  3. Divide the users in two groups. One group will work with Design A, the other one with Design B.
  4. The power of A/B Testing lies in the quantity. When testing websites or apps, you should certainly take advantage of tools that will make the subsequent analysis easier.
  5. Ask both groups to fulfill the same task or determine the questions and hypotheses that should be tested, e.g. how many users will manage to order your service or product.
  6. In case they are assigned a task, observe the how they cope with fulfilling the task and select the version that was easier for the users.
  7. Evaluate your questions and hypotheses.
  8. Use the more successful version in the actual practice. 

Keep in mind that...

  • you can test more than two versions
  • a more complicated testing of several versions can be also conducted with conjoint analysis
  • it is worth to monitor not only the results, but also their statistical relevance

Find out more


In the testing phase, you can use the following methods…

When you want to find out what is the current state of your service

When you want to find out why the users stop using your service

Download the book Service Design in Libraries

It includes detailed descriptions of case studies from both the Czech Republic and Norway.

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You will always have a ready help, which will tell you how to proceed, and which tools to prepare.

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