The best A/B testing tools ranked by pricing, feature depth, and who they’re actually built for. From free options like PostHog to enterprise platforms like Optimizely. No affiliate rankings. Just honest analysis from a team that runs CRO programs.
Last updated: March 2026 · Reading time: 16 min
| Tool | Starting Price | Free Tier | Best For | Stats Engine |
|---|---|---|---|---|
| VWO | $198/mo (Growth, annual) | Yes (limited) | Mid-market CRO teams | Bayesian |
| Optimizely | ~$36,000/year | No | Enterprise experimentation | Stats Accelerator |
| AB Tasty | ~$42/mo (estimate) | No | Ecommerce merchandising | Bayesian |
| PostHog | Pay-per-request | Yes (1M requests/mo) | Product teams, developers | Bayesian |
| Statsig | $12/service connection | Yes (free feature flags) | Product-led growth teams | Frequentist + Sequential |
| Convert | $199/mo (annual) | No | Privacy-focused teams | Frequentist + Bayesian |
| LaunchDarkly | $10/seat/mo + usage | Yes (limited) | DevOps, feature management | Bayesian |
| Kameleoon | ~$35,000/year | No | Enterprise personalization | Bayesian |
| Split (Harness) | Free for developers | Yes | Engineering teams | CUPED + Sequential |
| Zoho PageSense | $20/mo | 15-day trial | Small businesses, Zoho users | Frequentist |
| Omniconvert | $273/mo | No | Ecommerce CRO | Frequentist |
“The biggest mistake teams make when choosing an A/B testing tool is buying based on features they’ll use ‘someday.’ Start with the tool that matches your current test volume and team size. You can always migrate to a more powerful platform when you’re running 10+ tests per month consistently.” Hardik Shah, Founder of ScaleGrowth.Digital
PostHog is the best free A/B testing tool in 2026. It offers 1 million feature flag requests per month with all features included, no paywalled capabilities. However, it requires code-based implementation. For a free option with a visual editor, VWO Starter offers limited free testing capabilities.
Google Optimize was discontinued on September 30, 2023. Google recommended AB Tasty, Optimizely, and VWO as replacements. The closest free alternatives are PostHog (1M free requests/month, code-based), VWO Starter (free, limited), and Zoho PageSense ($20/month, visual editor). No single tool perfectly replaces Optimize’s free-tier-plus-GA-integration combination.
A minimum of 1,000 visitors per variant per week is recommended for statistically valid A/B testing. For a standard two-variant test, that’s 2,000 weekly visitors to the tested page. Pages with fewer than 5,000 monthly visitors should test high-impact elements (headlines, CTAs) that produce large conversion lifts, not minor design tweaks.
Frequentist A/B testing requires a fixed sample size set before the test starts. You can’t peek at results early without inflating false positive rates. Bayesian A/B testing updates probabilities continuously as data arrives, making it safer to check results during the test. Bayesian methods typically reach conclusions 20-40% faster. Most modern tools (VWO, PostHog, AB Tasty) use Bayesian methods by default.
Yes. Most A/B testing tools work with WordPress through a JavaScript snippet added to your site header. VWO, AB Tasty, and Optimizely all provide WordPress plugins or tag-based installation. PostHog and Statsig require code-level integration through your theme or a custom plugin. Zoho PageSense offers the simplest WordPress setup with its tag-based installation.
We build and run conversion rate optimization programs that combine testing, analytics, and user research. From tool selection to test prioritization to statistical analysis. Get a CRO Audit Talk to Us