# AB SHARK

> Free, open-source A/B test significance calculator and sample-size planner. Compute p-values, confidence intervals, conversion lift, and required sample size with rigorous statistics. No signup required.

AB SHARK is a focused web tool for analyzing A/B tests: aggregated stats or CSV upload in, p-values, confidence intervals, and effect sizes out. It also includes a pre-test sample-size planner and a methodology blog.

## Tools

- [A/B Test Analyzer](https://abshark.com/analyze): Run analysis on aggregated counts or raw CSV data. Returns p-values, confidence intervals, lift, and effect sizes.
- [Sample-Size Planner](https://abshark.com/plan): Compute the sample size required to detect a target lift with given alpha and power.

## Blog

- [Blog index](https://abshark.com/blog): Articles on A/B testing methodology, statistics, variance reduction, and experiment design.

## Optional

- [RSS feed](https://abshark.com/feed.xml)
- [Sitemap](https://abshark.com/sitemap.xml)