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Flagsmith vs GNAT Pro

Flagsmith logo

Flagsmith

Software Development

Open-source feature flag and remote config platform

From
Free
Rated
-
Full reviewWebsite
GNAT Pro logo

GNAT Pro

Developer Tools

Software development environments and toolchains for Ada, C/C++ and Rust

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Flagsmith has a free tier, so it costs nothing to try first.
  • Each has a real cost: Flagsmith the Free plan supports only a single team member, limiting collaboration for small teams.; GNAT Pro no pricing published on website; requires contacting AdaCore directly for quotes

Where they differ

Only the attributes on which Flagsmith and GNAT Pro actually diverge.

Attributes where Flagsmith and GNAT Pro differ
AttributeFlagsmithGNAT Pro
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
Platformsweb, apiWeb
CategorySoftware DevelopmentDeveloper Tools

Identical on both: 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

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

Only in GNAT Pro

Nothing recorded that Flagsmith does not also cover.

What people use each for

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

Flagsmith

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

GNAT Pro

  • Building certified avionics software meeting DO-178B/C standardsnot Flagsmith
  • Developing automotive embedded systems with ISO-26262 compliancenot Flagsmith
  • Integrating Ada, C/C++, and Rust components in single codebasenot Flagsmith
  • Managing software supply chain vulnerabilities and SBOMsnot Flagsmith
  • Supporting long-lived software systems spanning decadesnot 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.

GNAT Pro

  • No pricing published on website; requires contacting AdaCore directly for quotes
  • Vendor indicates per-user, per-year subscription model but does not disclose specific costs

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

GNAT Pro

On request

No published plan breakdown. See the GNAT Pro review.

Which should you pick?

Choose Flagsmith if

  • You need feature flags.
  • You want to start without paying.
  • You work on web, api.
  • You also want segments.
Flagsmith review

Choose GNAT Pro if

Nothing in the data separates GNAT Pro from Flagsmith on the points above - pick on price and on how each one feels to use.

GNAT Pro review

Questions people ask

Is Flagsmith or GNAT Pro better?
Neither clearly leads. Flagsmith starts at Free and GNAT Pro at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Flagsmith or GNAT Pro?
Flagsmith has a free tier; the other does not. Paid plans start at Free for Flagsmith and On request for GNAT Pro.
Does Flagsmith or GNAT Pro run on more platforms?
Flagsmith runs on web, api. GNAT Pro runs on Web.
Can I use Flagsmith for free?
Yes. Flagsmith has a free tier, so you can try it without paying. GNAT Pro starts at On request.
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 GNAT Pro is typically brought in for.
What can Flagsmith do that GNAT Pro cannot?
Flagsmith covers Feature flags, Segments, A/B testing, Scheduled 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
GNAT Pro: How much does GNAT Pro cost?

GNAT Pro pricing is not published on the website. Customers must request a pricing quote by contacting AdaCore directly or speaking with a GNAT Pro expert.

Source
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
GNAT Pro: What is GNAT Pro licensing model?

GNAT Pro is sold on a per-user, per-year basis with no license locks. Customers can request pricing for their specific needs.

Source
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
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