Free email test planner
Your last A/B winner may be noise.
Your platform declares a winner on every test, even when the list is too small to tell. Upload a campaign export and see which test to run next, and how many sends it takes to get an answer you can believe.
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Sample-size calculator
How many people a test needs before you can believe the result, at 95% confidence and 80% power.
6,510 people per version.
- 20% split7 sends to get there. One send alone detects a 27% difference.
- 50% split3 sends to get there. One send alone detects a 17% difference.
- 100% split2 sends to get there. One send alone detects a 12% difference.