Free tools
Calculators for planning and reading experiments. Free, no account, and everything is calculated in your browser.
A/B test sample size calculator
How many participants each variant needs to detect the effect you care about, and how long recruiting them takes.
A/B/n test results calculator
Compare three to six variants of a finished test: every pair, with a correction for multiple comparisons.
Minimum detectable effect calculator
The smallest conversion increase your traffic and test duration can detect reliably, as a relative uplift and in percentage points.