Experimento is the field journal for conversion and product experimentation. Real A/B teardowns, the maths behind significance, and the playbooks that move a funnel, written by people who ship the tests.
A practical 2026 comparison of the best A/B testing tools by what each one is actually good at, from Optimizely and VWO to GrowthBook and PostHog.
A practical 2026 comparison of the best A/B testing tools by what each one is actually good at, from Optimizely and VWO to GrowthBook and PostHog.
Nine real Optimizely alternatives for A/B testing and CRO in 2026, with pricing, strengths, and the exact team each one fits best.
A practical VWO vs Optimizely comparison covering pricing, statistics engines, features, and which platform fits mid-market and enterprise teams in 2026.
Free A/B test sample size calculator. Enter your baseline conversion rate and the smallest lift worth detecting to get the visitors per variation you need for a valid test.
Free A/B test significance calculator. Enter visitors and conversions for your control and variant to get the p-value, confidence level, and whether the result is statistically significant.
Free A/B test duration calculator. Enter your traffic, baseline conversion rate, and target lift to find out how many days your A/B test needs to run to reach significance.
Free CRO ROI calculator. Enter your traffic, conversion rate, and average order value to see the extra monthly and annual revenue a conversion rate improvement would generate.
UK conversion rate optimisation guide: real benchmarks, A/B test sample sizes, PECR and DUAA consent rules, checkout fixes, and a low-traffic playbook.
Free minimum detectable effect (MDE) calculator. Enter the visitors per variation you can realistically get and your baseline conversion rate to find the smallest lift an A/B test can reliably detect.