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Software Development · head to head

Flagsmith vs GrowthBook

Flagsmith logo

Flagsmith

Software Development

Open-source feature flag and remote config platform

From
Free
Rated
-
Full reviewWebsite
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

The short version

  • Each has a real cost: Flagsmith the Free plan supports only a single team member, limiting collaboration for small teams.; 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.
  • They diverge on capability: Flagsmith covers Segments, GrowthBook covers Warehouse-native analysis.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Flagsmith and GrowthBook actually diverge.

Attributes where Flagsmith and GrowthBook differ
AttributeFlagsmithGrowthBook
Pricing modelfreemiumPer user per month
Platformsweb, apiWeb, Self-hosted, Docker
CategorySoftware DevelopmentTesting

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Flagsmith

  • Segments
  • A/B testing
  • Scheduled flags
  • SDKs
  • SAML/SSO

Only in GrowthBook

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

Both cover

  • Feature flags

What people use each for

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

Flagsmith

  • Gradual feature rollouts across environmentsnot GrowthBook
  • Remote configuration without redeploying codenot GrowthBook
  • Running A/B tests tied to feature flagsnot GrowthBook
  • Self-hosting feature flags for data residency requirementsnot GrowthBook

GrowthBook

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

Where each one falls short

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

Flagsmith

  • The Free plan supports only a single team member, limiting collaboration for small teams.
  • Exceeding request limits triggers overage charges after a one-time 30-day grace period.
  • Enterprise-grade SSO and governance are locked behind the Scale-Up and Enterprise tiers.
  • Self-hosting requires operating and updating the platform yourself, unlike a fully managed SaaS competitor.

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.

Pricing, plan by plan

Flagsmith

Free
  • FreeFree
    • Up to 50,000 requests/month
    • 1 team member
    • Unlimited feature flags, environments, identities and segments
  • Start-Up$45/month
    • Up to 1,000,000 requests/month
    • 3 team members
    • Scheduled flags, 2FA, A/B testing, integrations, email support
  • Scale-Up$300/month
    • 5,000,000+ requests/month
    • 5-20 team members
    • SAML/SSO, governance features, priority support

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

Which should you pick?

Choose Flagsmith if

  • You need segments.
  • You want to start without paying.
  • You work on web, api.
  • You also want a/b testing.
Flagsmith review

Choose GrowthBook if

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

Questions people ask

Is Flagsmith or GrowthBook better?
Neither clearly leads. Flagsmith starts at Free and GrowthBook at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Flagsmith or GrowthBook?
Flagsmith starts at Free and GrowthBook at Free.
Does Flagsmith or GrowthBook run on more platforms?
Flagsmith runs on web, api. GrowthBook runs on Web, Self-hosted, Docker.
Can I use Flagsmith for free?
Both have a free tier, so you can try either at no cost before committing.
What is Flagsmith best used for?
Flagsmith is most often used for gradual feature rollouts across environments, remote configuration without redeploying code, running a/b tests tied to feature flags, self-hosting feature flags for data residency requirements. Of those, gradual feature rollouts across environments and remote configuration without redeploying code are not what GrowthBook is typically brought in for.
What can Flagsmith do that GrowthBook cannot?
Flagsmith covers Segments, A/B testing, Scheduled flags, SDKs. GrowthBook covers Warehouse-native analysis, Reusable metric definitions, Bayesian and frequentist engines, CUPED variance reduction. Both handle Feature flags.

Answered from the vendors’ own pages

Flagsmith: What does Flagsmith cost?

Flagsmith has a Free plan, a Start-Up plan from $40-45/month, a Scale-Up plan from $250-300/month, and custom Enterprise pricing.

Source
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.

Flagsmith: Is there a free plan, and what are its limits?

The Free plan supports up to 50,000 requests per month and 1 team member, with unlimited feature flags, environments, identities and segments.

Source
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.

Flagsmith: How is usage metered?

Usage is metered by monthly API requests; exceeding a plan's limit triggers overage charges starting around $50 per million requests, with a 30-day grace period the first time a paid plan exceeds its limit.

Source
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.

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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