Free resources and calculators
Free tools for testing properly
The calculators and simulators we use to plan and check experiments. Free to use, no sign-up.
Calculators
Plan and read your tests: sample size, duration, detectable effects and results.
Experiment best practices
Interactive simulators that show the most common ways tests go wrong, and how to avoid them.
- Significance Testing
- Peeking Checks
- Statistical Guardrails
- Imbalanced Flights
- Metric Variability & Detectability
Advanced techniques
The methods experienced experimentation teams use to get clearer answers from less traffic.