Guide

Plain-English answers.

A plain-English guide also ships inside the plugin, so you can read the essentials in wp-admin too.

How long should a test run?

Run full weeks so weekday and weekend visitors are both counted. Stop when the planned sample is reached, not when one variant looks ahead on day two. Same method as the plugin: two-sided 95% confidence, 80% power.

Sample-size calculator

Type your own numbers; the result updates as you type.

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You need

16,312visitors in total

About 17 days at your traffic

Per variant: (1.96 + 0.8416)² × [p₁(1 - p₁) + p₂(1 - p₂)] / (p₂ - p₁)², lift relative to the baseline; total = per variant × variants. The full calculator adds a confidence setting and shareable results.

Stuck on something?

The FAQ covers licensing, privacy and compatibility, and support is an email away.