This website contains a collection of tools useful for running & evaluating online A/B tests.

Has your A/B test already begun?

Statistical Significance Calculator

This is useful for tests that are already running.

Control Group
Variant #1
Variant #2
Variant #3
Variant #4

Sample Size Calculator

For tests that have not yet started.

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Control CTR
Desired Improvement

This website provides tools that can help you make sense of A/B testing. This calculator is different from others in a couple of ways:

  • Inputs are specific to website A/B testing.
  • Works for landing pages, ads, conversion pages, etc.
  • Helps with test planning as well as evaluating tests that have already begun.
  • Calculates both confidence interval and remaining sample size for up to 4 variations.