Best A/B Testing Platforms of 2026

GrowthBook is the open-source warehouse-native A/B testing platform for teams that already store event data in their warehouse. Founded in 2020, GrowthBook ships under MIT license with warehouse-native stats; the platform queries your existing data warehouse rather than ingesting events into a proprietary store.

Three tiers serve three buyer profiles. The Self-host free tier ships open-source MIT with unlimited self-host plus Bayesian and frequentist stats plus warehouse-native backends. The Cloud Pro tier ships at $20 per seat monthly with hosted GrowthBook plus SSO plus audit logs plus priority support. The Enterprise tier ships custom contract with SAML SSO plus dedicated CSM plus on-prem deployment.

The load-bearing wedge is the warehouse-native architecture. Where Optimizely, VWO, Statsig, and Convert ingest events into proprietary stores, GrowthBook queries your existing warehouse (BigQuery, Snowflake, Postgres). For teams already running data warehouses, this eliminates per-event pricing entirely; GrowthBook charges per seat ($20/mo Cloud Pro), not per event. The catch is the warehouse dependency. Teams without existing warehouse infrastructure face higher setup overhead than turnkey alternatives. For teams already on BigQuery or Snowflake running 10M+ monthly events, GrowthBook Cloud Pro at $20/seat/mo eliminates per-event pricing dramatically.

PostHog is the open-source product analytics platform with bundled A/B testing for teams wanting one tool covering analytics plus experimentation plus session replay. Founded in 2020 in London and backed by Y Combinator, PostHog positions around the all-in-one product platform shape with MIT-licensed self-hosting plus generous free cloud tier.

Three tiers serve three buyer profiles. The Free cloud tier ships 1M events monthly with product analytics plus session replay plus feature flags plus A/B testing. The Pay-as-you-go tier ships usage-based at $0.000248 per event after 1M plus $0.005 per recording after 5K with all product features. The Self-host tier ships open-source MIT with unlimited self-host plus all features.

The load-bearing wedge is the bundled product platform. Where Optimizely, VWO, GrowthBook, and Statsig target A/B testing primarily, PostHog bundles A/B with product analytics (events, funnels, retention) plus session replay plus heatmaps in one platform. For early-stage teams wanting one tool covering multiple product needs, PostHog eliminates tool sprawl. The catch is the breadth-vs-depth tradeoff. PostHog A/B testing is solid but lacks depth of dedicated platforms (Optimizely sequential testing, GrowthBook warehouse-native). For early-stage teams wanting bundled product platform with A/B included, PostHog Free is the most generous in lineup.

Statsig is the free-tier feature flag plus experimentation platform for developer-friendly modern teams. Founded in 2021 in Bellevue by ex-Facebook engineering leads, Statsig positions around the developer experience with unlimited free feature flags plus generous free experimentation.

Three tiers serve three buyer profiles. The Free tier ships 1M events monthly with unlimited feature flags plus experimentation plus auto-tune for stats power. The Pro tier ships at $0.03 per 1K additional events with 10K MAUs free plus advanced experimentation plus CUPED variance reduction. The Enterprise tier ships custom contract with SOC 2 plus HIPAA plus SAML SSO plus dedicated CSM.

The load-bearing wedge is the free-tier viability. Where Optimizely costs $36K/yr and VWO Growth costs $3.7K/yr, Statsig Free covers actual production use for teams generating under 1M events monthly. For early-stage startups and engineering-heavy teams running feature-flag experiments, Statsig Free is the cheapest production-ready path. The catch is the per-event pricing at scale. Teams generating 100M+ events monthly hit Pro tier costs that approach VWO Growth or Optimizely Web pricing. For developer-friendly teams under 5M events monthly, Statsig Free or Pro covers the use case better than any paid enterprise tier.

Optimizely is the default A/B testing platform for most paid enterprise teams. Founded in 2010 in San Francisco by Dan Siroker (an Obama 2008 campaign analytics lead), Optimizely serves the largest mainstream enterprise A/B testing market with institutional contracts and the deepest statistical engine.

Three tiers serve three buyer profiles. The Web Experimentation tier ships visual A/B and multivariate plus stats engine with sequential testing plus AI-powered targeting at $36K/yr institutional. The Feature Experimentation tier ships server-side flags plus experiments plus SDKs for all major languages at $50K/yr. The Personalization tier ships 1:1 personalization plus AI audience segmentation plus multi-armed bandit at $60K/yr.

The load-bearing wedge is mainstream brand recognition plus statistical sophistication. Optimizely set the standard for sequential testing and AI-powered targeting; competitors followed. The catch is the institutional pricing. Web Experimentation at $36K/yr is significantly more expensive than VWO Growth at $314/mo ($3.7K/yr). For mid-market teams, VWO covers the use case at one-tenth the price; for enterprise teams needing sequential testing, AI targeting, and dedicated CSM, Optimizely is the historic standard. For mainstream enterprise CRO teams running 100+ experiments per year, Optimizely Web Experimentation covers the use case better than VWO or Convert.

VWO is the mid-market visual A/B testing platform for SMB ecommerce optimization. Founded in 2009 in India by Wingify, VWO positions around the visual editor plus heatmaps bundle that targets non-developer marketing and product teams.

Three tiers serve three buyer profiles. The Starter free tier ships 50K MAU plus visual editor plus basic A/B testing plus heatmaps. The Growth tier ships at $314 monthly with 100K MAU plus multivariate testing plus custom targeting plus funnels. The Pro tier ships at $690 monthly with 200K MAU plus server-side testing plus personalization plus advanced segmentation.

The load-bearing wedge is the bundled heatmaps. Where Optimizely targets pure A/B testing and Statsig targets feature-flag experimentation, VWO bundles A/B testing with session-replay-style heatmaps in one platform. For SMB ecommerce teams optimizing product pages, the integrated heatmap workflow eliminates a second tool (Hotjar, Microsoft Clarity). The catch is the per-MAU pricing. Growth at $314/mo for 100K MAU works for sites under 100K monthly active users; high-traffic sites should evaluate enterprise tiers or warehouse-native alternatives. For SMB ecommerce CRO teams under 200K MAU, VWO Growth at $314/mo covers the use case at one-tenth the cost of Optimizely.

AB Tasty is the European CRO and experience optimization platform for global ecommerce teams headquartered in Europe. Founded in 2009 in Paris, AB Tasty positions around the European enterprise CRO shape with EU data residency by default plus deep CRO consulting services.

Three institutional tiers serve three enterprise profiles. Essentials ships at $2K-$5K monthly with visual A/B plus personalization plus EU data residency. Growth ships at $5K-$15K monthly with server-side plus custom audiences plus CRO consulting. Enterprise ships at $20K+ monthly with multi-region deployment plus SAML SSO plus dedicated CSM.

The load-bearing wedge is the European CRO positioning. Where Optimizely, VWO, and Convert target US and global markets, AB Tasty targets European enterprise ecommerce with EU residency by default plus French and German support plus EU regulatory expertise. For European enterprise ecommerce teams, AB Tasty removes the residency negotiation step that US platforms require. The catch is the enterprise-only pricing. Essentials at $3K/mo is the entry; for SMB teams, VWO Growth at $314/mo covers better at one-tenth the cost. For European enterprise CRO teams, AB Tasty Essentials covers the use case better than Optimizely or VWO Pro.

Convert is the privacy-first A/B testing platform for teams in regulated industries or with strict GDPR requirements. Founded in 2009, Convert positions around privacy-first architecture with no third-party cookies plus GDPR-compliant defaults plus EU data residency available.

Two tiers serve two buyer profiles. The Kickstart tier ships at $399 monthly with 100K tested users plus visual editor plus multivariate testing plus heatmap integration. The Scale tier ships at $699 monthly with 250K tested users plus custom audiences plus personalization plus multi-page funnels.

The load-bearing wedge is the privacy-first architecture. Where Optimizely, VWO, and Statsig rely on standard tracking pixels and cookies, Convert ships a no-third-party-cookie architecture aligned with GDPR Schrems II requirements. For teams in regulated industries (financial services, healthcare, EU public sector) or teams concerned about cookie deprecation, Convert eliminates the consent management overhead. The catch is the higher entry price. Kickstart at $399/mo is more expensive than VWO Growth at $314/mo for similar tested-user limits. For privacy-first teams in regulated industries, Convert Kickstart covers the use case better than VWO at the regulatory premium.