Optimizely vs PostHog

Side-by-side from the Top 11 rankings of The 11 Best A/B Testing Tools and The 11 Best Session Replay Tools. Last verified June 13, 2026.

The short answer

Optimizely ranks higher on Top 11 (#1 vs #7) for Growth teams running experiments / Teams watching real user sessions and heatmaps. The enterprise standard for its powerful stats engine and full-stack experimentation features.

At a glance

OptimizelyPostHog
Top 11 rank#1 / The 11 Best A/B Testing Tools#7 / The 11 Best Session Replay Tools
Score (out of 9.4)9.28
Best forEnterprise-scale experimentationOpen-source analytics suite
Pricing$$$$$ (Custom enterprise plans)$$ (Usage-based)
HQNew York, USASan Francisco, USA
Founded20092020

Optimizely

The enterprise standard for its powerful stats engine and full-stack experimentation features.

www.optimizely.com

See full entry in The 11 Best A/B Testing Tools

PostHog

Best open-source platform with replay, analytics, and feature flags.

posthog.com

See full entry in The 11 Best Session Replay Tools

Methodology and scoring weights live at /methodology. No vendor pays for placement — see about.