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GrowthBook vs Kong

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
Kong logo

Kong

APIs

Cloud-native API gateway and service connectivity platform

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.; Kong the Plus plan includes 1M API requests a month and charges $200 a month for each additional million
  • They diverge on capability: GrowthBook covers Feature flags, Kong covers API Gateway.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which GrowthBook and Kong actually diverge.

Attributes where GrowthBook and Kong differ
AttributeGrowthBookKong
Pricing modelPer user per monthsubscription
PlatformsWeb, Self-hosted, DockerLinux, Docker, Kubernetes
CategoryTestingAPIs
FoundedUnknown2010

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 GrowthBook

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

Only in Kong

  • API Gateway
  • Authentication & Authorization
  • Rate Limiting
  • Kubernetes
  • Consul
  • Eureka
  • PostgreSQL
  • Linux support

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 Kong
  • A data team that needs experiment results to reconcile exactly with the metrics reported in its BI toolnot Kong
  • A company with data residency or privacy constraints that cannot send user-level event data to a third-party vendornot Kong
  • Running long-tail experiments where sequential testing and CUPED shorten the time to a decision on low-traffic surfacesnot Kong

Kong

  • API gateway management and routingnot GrowthBook
  • API development and testingnot GrowthBook
  • Enterprise API security and governancenot 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.

Kong

  • The Plus plan includes 1M API requests a month and charges $200 a month for each additional million
  • Plus is capped at 10M requests a month, so growth past that forces an Enterprise contract
  • Plus limits published APIs to 20 and includes one Developer Portal, with a second at $200 a month
  • SSO and audit logging are Enterprise only
  • Enterprise pricing is custom and billed annually

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

Kong

Free
  • Kong Konnect Free TrialFree
    • 30-day free trial
    • Full enterprise functionality
    • Unlimited gateways
  • Kong Konnect Plus$null/month
    • Per gateway pricing billed monthly
    • Up to 5 Serverless Gateways, 2 Hybrid, 2 Dedicated Cloud Gateways
    • 1M API requests included per month
  • Kong Insomnia EssentialsFree
    • Unlimited projects and CLI access
    • Up to 3 Git Sync users
    • 1,000 mock server requests per month
  • Kong Insomnia Pro$12/month
    • Unlimited users with Git Sync access
    • Unlimited organizations
    • RBAC

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 Kong if

  • You need api gateway.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes.
  • You also want authentication & authorization.
Kong review

Questions people ask

Is GrowthBook or Kong better?
Neither clearly leads. GrowthBook starts at Free and Kong at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, GrowthBook or Kong?
GrowthBook starts at Free and Kong at Free.
Does GrowthBook or Kong run on more platforms?
GrowthBook runs on Web, Self-hosted, Docker. Kong runs on Linux, Docker, Kubernetes.
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 Kong is typically brought in for.
What can GrowthBook do that Kong cannot?
GrowthBook covers Feature flags, Warehouse-native analysis, Reusable metric definitions, Bayesian and frequentist engines. Kong covers API Gateway, Authentication & Authorization, Rate Limiting, Kubernetes.

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.

Kong: Does Kong offer a free trial?

Yes, Kong Konnect offers a 30-day free trial with full enterprise functionality, unlimited gateways, and no credit card required.

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.

Kong: How much does Kong Insomnia Pro cost?

Kong Insomnia Pro is $12 per user per month with 15% savings available for annual billing.

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.

Kong: What are Kong Konnect Plus API request limits?

Kong Konnect Plus includes 1M API requests per month; additional requests cost $200 per 1M (maximum 10M per month).

Source
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.

Kong: What is included in Kong Insomnia Enterprise?

Kong Insomnia Enterprise is $45 per user per month with SSO, SCIM, vault integrations, unlimited mock server requests, and Konnect integration.

Source
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