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.
The conversion rate formula, three worked examples, the GA4 key event rate change, and why UK consent rules skew your number.
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.
The conversion rate formula, three worked examples, the GA4 key event rate change, and why UK consent banners skew your number.