Outtest vs GrowthBook
GrowthBook and Outtest both run A/B tests, but GrowthBook is a toolkit for your team and Outtest is a service run by AI agents. With GrowthBook, engineers add an SDK and wrap changes in feature flags or use the AI visual editor, and a data person writes SQL so results come from your own warehouse. You decide what to test and when to stop. It's open source, so you can also host it yourself for free.
Outtest's agents read your analytics and payment data, find where the funnel loses the most money, write the new version, run it and call the winner on revenue per visitor from your payment tool. It focuses on marketing surfaces such as landing pages, pricing, trials, cancel flows, Meta ads and SEO, and costs from $29 a month for 3 tests. Outtest is new. GrowthBook has been around since 2020 and names Dropbox and Khan Academy among its users.
At a glance
| Outtest | GrowthBook | |
|---|---|---|
| Best for | Founders and small teams who want tests run for them and judged on real revenue, without a CRO specialist. | Data and engineering teams that want experiment results computed from their own data warehouse, or want to self-host for free. |
| Price | From $29/month (3 tests a month). 20% off yearly. | Free cloud Starter plan for up to 3 users, and a free self-hosted open-source version. Pro is $40 per seat a month for up to 30 users. Enterprise, cloud or self-hosted, is custom. |
| Free plan or trial | No free plan or trial | Free plan |
| AI builds the test versions | Yes | Yes |
| Judges tests on revenue from your payment tool | Yes | Partly |
| Visual editor | No | Yes |
| Server-side tests | Partly | Yes |
| Stats engine | Bayesian, on revenue per visitor | Both (Bayesian by default, frequentist with optional sequential testing, CUPED on either) |
| Payment integrations | Stripe, Shopify, Polar, Whop, Paddle, Lemon Squeezy, Gumroad, Dodo Payments, Creem, RevenueCat, Chargebee | Shopify |
Pick GrowthBook if
- You want to self-host your experimentation stack, or you need open-source code you can audit.
- Your metrics live in a warehouse such as BigQuery or Snowflake and someone on the team writes SQL.
- You need feature flags and server-side experiments across web, mobile and backend code.
- You want seat-based pricing that doesn't grow with traffic.
- You want to choose between Bayesian and frequentist stats yourself.
Pick Outtest if
- You don't have a warehouse or a data person, and you want revenue pulled straight from Stripe, Paddle, Shopify or another payment tool.
- You want AI agents to decide what to test, build it, run it and call it, not only help edit a page.
- You test marketing surfaces such as landing pages, pricing, trial length, cancel flows, Meta ad copy and SEO page groups.
- You want changes to pricing, checkout and cancel flows held for your approval by default.
The verdict
GrowthBook is the better pick for data-led teams that own a warehouse and want an open-source, self-hostable platform for flags and experiments. Outtest is the better pick for founders and marketers who want tests run for them and judged on revenue from the payment tool, with no SQL. The two can sit side by side, GrowthBook for product flags and Outtest for the marketing site.
Questions people ask
Is GrowthBook free?+
Yes, in two ways. The open-source version is free to self-host with unlimited users, and the cloud Starter plan is free for up to 3 users. Pro is $40 per seat a month, and Enterprise is custom.
Can I self-host GrowthBook?+
Yes. The repository ships a Docker Compose setup, so you can clone it and run docker compose up. Most of the code is MIT licensed, and some enterprise features sit under a separate commercial license.
Does GrowthBook use Bayesian or frequentist statistics?+
Both. Bayesian is the default, and you can switch to frequentist per organization or project. Sequential testing is available for frequentist analysis, and CUPED works with either engine.
Does GrowthBook need a data warehouse?+
It's built to query your own warehouse, such as BigQuery, Snowflake, Redshift, Databricks or Postgres. If you don't have one, cloud plans include a managed warehouse with 1M events a month on Starter and 2M on Pro.
Can GrowthBook measure revenue from Stripe?+
Not directly. There's no native Stripe connector, so revenue has to reach your warehouse or the managed warehouse first, and then you define a SQL metric such as a SUM of order totals. Outtest reads revenue straight from Stripe and other payment tools and judges every test on revenue per visitor.
Sources
Checked on 28 September 2026 from GrowthBook's own pages. Prices and features change; check GrowthBook's site before you buy.
- growthbook.io/pricing
- growthbook.io/
- growthbook.io/about
- github.com/growthbook/growthbook
- docs.growthbook.io/statistics/overview
- docs.growthbook.io/lib
- docs.growthbook.io/warehouses
- docs.growthbook.io/app/metrics
- docs.growthbook.io/integrations
- docs.growthbook.io/integrations/shopify
- growthbook.io/platform/visual-editor
Let Outtest run your split tests
AI agents read your analytics and payments, find where you lose the most money, build the fix and test it. Every test is judged on revenue, not clicks. Plans from $29 a month.