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testcritic

GrowthBook vs Optimizely

Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.

Entry price

From $40 per seat/month (cloud Pro, up to 30 users and 3 projects)

Free tier

Quote on request

Quote only

What drives the bill

The metric that actually scales your invoice.

Seat-based rather than usage-based, so cost tracks the number of people using the platform rather than your traffic — which is why it stays dramatically cheaper than the commercial platforms at scale, especially self-hosted.

Enterprise annual contracts, commonly in the tens of thousands and up. Priced by traffic and modules.

Free tier

Self-hosted open source is free with unlimited users on 1 project; the cloud Starter tier is free for up to 3 users.

No free tier.

Open source

MIT (core)

Self-hostable

No-code authoring

Languages

JavaScriptTypeScriptPythonJavaC#GoRubyPHPSwiftKotlin
JavaScriptPythonJavaC#GoRubyPHPCodeless

Platforms

WebAPIiOSAndroid
WebAPIiOSAndroid

Fits teams

StartupScale-up / mid-marketEnterprise
Enterprise

Adoption

Widely used

GrowthBook · since 2021

Widely used

Optimizely · since 2010

Strengths

  • Warehouse-native by design — no duplicate event pipeline and no data leaving your control.
  • Self-hosting removes per-user-volume pricing entirely.
  • Both Bayesian and frequentist engines with sequential testing support.
  • The most capable visual editor for non-technical experiment authoring.
  • Deep personalisation and audience-targeting features.
  • Established statistics with sequential testing, so peeking is handled correctly.

Limitations

  • Requires a working data warehouse and someone who can define metrics in SQL.
  • Self-hosting is operational work you own.
  • Less polished governance and approval tooling than LaunchDarkly.
  • Expensive, with a suite-oriented sales motion that pushes adjacent products.
  • Client-side testing causes flicker and is increasingly blocked by browsers and blockers.
  • Heavyweight for teams that only need a handful of experiments.

Best for

Data-mature teams that already have a warehouse and want to avoid volume-based pricing.

Large marketing organisations running continuous experimentation on high-traffic sites.

All of these integrate with: Snowflake, Segment, Slack.

Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.