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Testing · head to head

GrowthBook vs Testsigma

GrowthBook logo

GrowthBook

Testing

Open source feature flags and A/B testing that run experiment analysis inside your own data warehouse

From
Free
Rated
-
Full reviewWebsite
Testsigma logo

Testsigma

Testing

Natural language test automation for web, mobile and API with a self hosted open source edition

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: GrowthBook warehouse-native analysis is only an advantage if you have a warehouse with clean event data in it; without one, GrowthBook has nothing to compute against and you are back to buying an event-collecting platform.; Testsigma the natural language layer is a fixed vocabulary rather than real English, so testers spend the first weeks learning which phrasings the parser accepts, which is learning a language after all.
  • They diverge on capability: GrowthBook covers Feature flags, Testsigma covers Natural language authoring.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which GrowthBook and Testsigma actually diverge.

Attributes where GrowthBook and Testsigma differ
AttributeGrowthBookTestsigma
PlatformsWeb, Self-hosted, DockerWeb, iOS, Android, Linux

Identical on both: starting price (Free), pricing model (Per user per month), free tier (Yes), user rating (Not yet rated), category (Testing).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in GrowthBook

  • Feature flags
  • Warehouse-native analysis
  • Reusable metric definitions
  • Bayesian and frequentist engines
  • CUPED variance reduction
  • Visual editor
  • Self-hosting
  • Guardrail metrics

Only in Testsigma

  • Natural language authoring
  • Unified web, mobile and API tests
  • Self hosted community edition
  • Cloud device and browser grid
  • Data driven runs
  • Custom functions

What people use each for

The jobs each tool is most often brought in to do.

GrowthBook

  • An engineering team that wants feature flags without a per-monthly-active-user bill that grows with product successnot Testsigma
  • A data team that needs experiment results to reconcile exactly with the metrics reported in its BI toolnot Testsigma
  • A company with data residency or privacy constraints that cannot send user-level event data to a third-party vendornot Testsigma
  • Running long-tail experiments where sequential testing and CUPED shorten the time to a decision on low-traffic surfacesnot Testsigma

Testsigma

  • A team maintaining separate Selenium and Appium suites that wants one place for web and native mobile coveragenot GrowthBook
  • Organisations that must keep test data and execution on premises for regulatory reasonsnot GrowthBook
  • QA groups with manual testers being asked to automate without first learning Javanot GrowthBook
  • Evaluating low code test automation properly before committing budget, by running the free edition against the real applicationnot GrowthBook

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

GrowthBook

  • Warehouse-native analysis is only an advantage if you have a warehouse with clean event data in it; without one, GrowthBook has nothing to compute against and you are back to buying an event-collecting platform.
  • Metrics are SQL, so a marketing or product team without data engineering support cannot define or fix them, and a badly written metric silently produces a confident wrong answer.
  • Cloud Pro bills per seat and then adds CDN request and bandwidth overages, so a high-traffic site can find the variable component exceeds the seat cost it budgeted for.
  • Self-hosting means you own the Mongo database, the SDK endpoint availability and the upgrade path, and a flag service that is down is a production incident, not an analytics inconvenience.
  • The statistics engine exposes real choices, Bayesian versus frequentist, sequential testing, variance reduction, and the tool will not stop a team that configures them wrongly, so it rewards statistical literacy and punishes its absence.

Testsigma

  • The natural language layer is a fixed vocabulary rather than real English, so testers spend the first weeks learning which phrasings the parser accepts, which is learning a language after all.
  • Anything conditional or arithmetic falls through to custom Java or JavaScript, and that code lives in the platform editor rather than your repository, where it gets no code review and no version history you control.
  • The community edition lags the cloud product and is not the version the vendor demonstrates, so a self hosted evaluation can understate or overstate what you would actually buy.
  • Cloud execution is billed separately from authoring seats, so a suite that grows from two hundred to two thousand tests changes the bill without anyone changing the plan.
  • Support and engineering are concentrated in Indian time zones, which slows incident turnaround for teams working in the Americas.

Pricing, plan by plan

GrowthBook

Free
  • Open source (self-hosted)Free
    • Unlimited users, feature flags and experiments
    • One project
    • MIT licensed, you run the infrastructure
  • Starter (cloud)Free
    • Up to 3 users
    • 1 project
    • Unlimited flags, experiments and traffic
  • Pro (cloud)$40/month
    • Per seat, up to 50 users
    • 3 projects
    • CDN overage at $10 per million requests beyond the included allowance
  • Enterprise$undefined/year
    • Unlimited users and projects
    • SSO, audit logs and advanced permissions
    • Available on cloud or self-hosted

Testsigma

Free
  • Community Edition$undefined/month
    • Self hosted, open source, no licence fee
    • You supply the infrastructure and the browser or device grid
  • Cloud$undefined/month
    • Priced per authoring user with additional charges for parallel cloud executions and device minutes
    • Published tiers exist but the figures that matter at team scale come from sales

Which should you pick?

Choose GrowthBook if

  • You need feature flags.
  • You want to start without paying.
  • You work on Web, Self-hosted, Docker.
  • You also want warehouse-native analysis.
GrowthBook review

Choose Testsigma if

  • You need natural language authoring.
  • You want to start without paying.
  • You work on Web, iOS, Android, Linux.
  • You also want unified web, mobile and api tests.
Testsigma review

Questions people ask

Is GrowthBook or Testsigma better?
Neither clearly leads. GrowthBook starts at Free and Testsigma at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, GrowthBook or Testsigma?
GrowthBook starts at Free and Testsigma at Free.
Does GrowthBook or Testsigma run on more platforms?
GrowthBook runs on Web, Self-hosted, Docker. Testsigma runs on Web, iOS, Android, Linux.
Can I use GrowthBook for free?
Both have a free tier, so you can try either at no cost before committing.
What is GrowthBook best used for?
GrowthBook is most often used for an engineering team that wants feature flags without a per-monthly-active-user bill that grows with product success, a data team that needs experiment results to reconcile exactly with the metrics reported in its bi tool, a company with data residency or privacy constraints that cannot send user-level event data to a third-party vendor, running long-tail experiments where sequential testing and cuped shorten the time to a decision on low-traffic surfaces. Of those, an engineering team that wants feature flags without a per-monthly-active-user bill that grows with product success and a data team that needs experiment results to reconcile exactly with the metrics reported in its bi tool are not what Testsigma is typically brought in for.
What can GrowthBook do that Testsigma cannot?
GrowthBook covers Feature flags, Warehouse-native analysis, Reusable metric definitions, Bayesian and frequentist engines. Testsigma covers Natural language authoring, Unified web, mobile and API tests, Self hosted community edition, Cloud device and browser grid.

Answered from the vendors’ own pages

GrowthBook: Is the self-hosted version actually usable, or crippled?

It is genuinely usable: unlimited users, flags and experiments on one project under an MIT licence. The paid tiers add multiple projects, SSO, audit logs and support.

Testsigma: Is the open source edition genuinely usable in production?

Yes for self hosted execution, though it trails the cloud version on newer features and you maintain the grid yourself.

GrowthBook: Do I need a data warehouse?

For experiment analysis, effectively yes. Feature flagging works without one, but the reason to choose GrowthBook over a flag-only tool is the warehouse-native statistics.

Testsigma: Do testers need to know Selenium?

Not to write ordinary steps. They will need someone who does as soon as the suite needs custom functions or awkward waits.

GrowthBook: How does the cost compare with LaunchDarkly or Optimizely?

GrowthBook charges per seat rather than per monthly active user or per tracked event, so cost stops scaling with traffic. At high volume that difference is large.

Testsigma: Can it test native iOS and Android applications?

Yes, through Appium underneath, on the hosted device grid or your own devices.

GrowthBook: Does it support mobile and server-side flags?

Yes, there are SDKs across JavaScript, React, Python, Go, Ruby, PHP, Java, Kotlin, Swift and more, covering client, server and mobile evaluation.

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