Tools

Experimentation & feature flags

12 tools compared: how each is priced, where it runs, and what to consider instead.

Tool Pricing model Free tier Open source
AB Tasty French web experimentation and personalization platform defaulting to Bayesian reporting, now merged with VWO under the Wingify brand. Quote only No No
Convert Experiences Privacy-focused web A/B testing platform that re-analyzes the same experiment under fixed-horizon frequentist, sequential frequentist or Bayesian statistics. Subscription No No
Datadog Experiments (formerly Eppo) Warehouse-native experimentation platform known for its CUPED implementation, acquired by Datadog in 2025 and rebranded Datadog Experiments. Quote only No No
Flagsmith Open-source (BSD-3-Clause) feature-flag and remote-config platform with basic A/B testing on flagged traffic, self-hostable or cloud. Free tier + paid Yes Yes
GrowthBook Open-source, warehouse-native experimentation and feature-flag platform offering both Bayesian and frequentist sequential analysis with CUPED. Free tier + paid Yes Yes
Harness Feature Management & Experimentation (formerly Split) Feature-flag platform with built-in statistical experimentation, acquired by Harness and sold as an Enterprise-plan module (Harness FME). Quote only No No
Kameleoon Web experimentation and feature-management platform supporting frequentist, sequential, and Bayesian analysis side by side. Quote only No No
LaunchDarkly Feature-flag management platform that also runs experiments on flagged rollouts, reading event data it collects itself rather than the warehouse. Subscription Yes No
Optimizely One of the original A/B testing platforms, now the experimentation module of a broader digital-experience suite (CMS, commerce, personalization). Quote only No No
Statsig Warehouse-native experimentation and feature-flag platform offering frequentist sequential testing, SPRT, Bayesian mode, and CUPED. Free tier + paid Yes No
Unleash Open-source feature-flag platform with rollout-based experimentation, moved from Apache-2.0 to AGPLv3 licensing in mid-2026. Free tier + paid Yes Yes
VWO Long-running web experimentation and personalization platform, using a Bayesian stats engine, now merging with AB Tasty under the Wingify brand. Quote only No No

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