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Testing · head to head

GrowthBook vs Janus Gateway

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
Janus Gateway logo

Janus Gateway

APIs

WebRTC gateway and media server for real-time communication

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.; Janus Gateway no commercial pricing published; open-source project without official commercial offerings
  • They diverge on capability: GrowthBook covers Feature flags, Janus Gateway covers WebRTC Gateway.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which GrowthBook and Janus Gateway actually diverge.

Attributes where GrowthBook and Janus Gateway differ
AttributeGrowthBookJanus Gateway
Pricing modelPer user per monthopen-source
PlatformsWeb, Self-hosted, DockerLinux, MacOS, BSD
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 Janus Gateway

  • WebRTC Gateway
  • Media Routing
  • Video Conferencing
  • RTP
  • SRTP
  • REST API
  • Linux support
  • MacOS 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 Janus Gateway
  • A data team that needs experiment results to reconcile exactly with the metrics reported in its BI toolnot Janus Gateway
  • A company with data residency or privacy constraints that cannot send user-level event data to a third-party vendornot Janus Gateway
  • Running long-tail experiments where sequential testing and CUPED shorten the time to a decision on low-traffic surfacesnot Janus Gateway

Janus Gateway

  • API Developmentnot GrowthBook
  • API Gatewaynot GrowthBook
  • API Testingnot GrowthBook
  • API Documentationnot GrowthBook
  • Microservicesnot 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.

Janus Gateway

  • No commercial pricing published; open-source project without official commercial offerings
  • Community-supported only; no vendor commercial support or SLA available

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

Janus Gateway

Free
  • Open SourceFree
    • Core WebRTC gateway
    • Community support

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 Janus Gateway if

  • You need webrtc gateway.
  • You want to start without paying.
  • You work on Linux, MacOS, BSD.
  • You also want media routing.
Janus Gateway review

Questions people ask

Is GrowthBook or Janus Gateway better?
Neither clearly leads. GrowthBook starts at Free and Janus Gateway at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, GrowthBook or Janus Gateway?
GrowthBook starts at Free and Janus Gateway at Free.
Does GrowthBook or Janus Gateway run on more platforms?
GrowthBook runs on Web, Self-hosted, Docker. Janus Gateway runs on Linux, MacOS, BSD.
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 Janus Gateway is typically brought in for.
What can GrowthBook do that Janus Gateway cannot?
GrowthBook covers Feature flags, Warehouse-native analysis, Reusable metric definitions, Bayesian and frequentist engines. Janus Gateway covers WebRTC Gateway, Media Routing, Video Conferencing, RTP.

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.

Janus Gateway: How much does Janus Gateway cost?

Janus Gateway has no pricing model; it is a free open-source WebRTC server developed by Meetecho. The general-purpose server is available for download at no cost. There are no subscription tiers or commercial licensing fees.

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.

Janus Gateway: Is Janus Gateway supported commercially?

Janus Gateway is community-supported open-source software with no official commercial support or SLA from the vendors. While Meetecho developed the project, users must rely on community documentation and forums for assistance.

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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