Free · No signup · Runs in your browser
Tools
Quick, focused utilities for the ideas in our stories — calculate it, don’t just read about it. More landing regularly.
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A/B Test Significance Calculator
Drop in the numbers from two variants and find out whether the difference is real — or just noise.
Experimentation
🧮Coming soon
Bayes / Base-Rate Calculator
How rare it is + how accurate the test is → your real odds after a positive.
Statistics
🔤Coming soon
Token Counter & Cost Estimator
Paste text → token estimate and what it costs across models.
AI & LLMs
📊Coming soon
Descriptive Statistics
Paste numbers → mean, median, spread, and a quick histogram.
Statistics
👥Coming soon
Sample Size Calculator
Baseline, effect, and power → how many users your test needs.
Experimentation
🔔Coming soon
Normal Distribution & Z-Score
Mean, SD, and a value → the shaded area and probability.
Statistics