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Developer Tools · head to head

ConfigCat vs Sardine

ConfigCat logo

ConfigCat

Developer Tools

Feature flag service priced per flag and environment with unlimited seats and unlimited monthly active users

From
Free
Free plan
Yes
Full reviewWebsite
Sardine logo

Sardine

Cybersecurity

Device intelligence and behaviour biometrics for fraud and compliance

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only ConfigCat has a free tier, so it costs nothing to try first.
  • Each has a real cost: ConfigCat there is no experimentation or statistical analysis engine, so teams wanting real A/B tests with significance testing must buy and integrate a separate analytics or experimentation product.; Sardine signal quality depends on the SDK being embedded in your own web and mobile clients, so fraud improvements become dependent on your app release cycle and any coverage gap is a blind spot.
  • They diverge on capability: ConfigCat covers Feature flags and configuration, Sardine covers Device intelligence.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which ConfigCat and Sardine actually diverge.

Attributes where ConfigCat and Sardine differ
AttributeConfigCatSardine
Starting priceFreeOn request
Pricing modelPer month by feature flag and environment countquote
Free tierYesNo
PlatformsWeb, API, iOS, Android, Node.js, .NET, Java, Python, GoWeb, iOS, Android
CategoryDeveloper ToolsCybersecurity

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 ConfigCat

  • Feature flags and configuration
  • Percentage rollouts
  • Targeting rules and segments
  • Unlimited seats
  • Global CDN delivery
  • Audit log
  • Public API and webhooks
  • SDKs across languages

Only in Sardine

  • Device intelligence
  • Behaviour biometrics
  • Scam detection
  • Onboarding risk scoring
  • AML transaction monitoring
  • Dispute and chargeback handling
  • Rules editor

What people use each for

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

ConfigCat

  • A consumer or mobile app with millions of users where per-MAU flag pricing would cost more than the flags are worthnot Sardine
  • A team that wants every engineer, product manager and support agent to have a login without paying per seatnot Sardine
  • Decoupling deployment from release with percentage rollouts and a kill switch, without buying an experimentation platformnot Sardine
  • A small team that needs ten flags permanently and can run indefinitely on the free tiernot Sardine

Sardine

  • A neobank losing money to authorised push payment scams where the customer genuinely approved the transfernot ConfigCat
  • A crypto exchange trying to detect accounts being operated by remote access rather than by their ownernot ConfigCat
  • A fintech seeing synthetic identity signups that pass document verification but share device characteristicsnot ConfigCat
  • A lender wanting first party fraud signals at application time that a credit bureau file does not containnot ConfigCat

Where each one falls short

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

ConfigCat

  • There is no experimentation or statistical analysis engine, so teams wanting real A/B tests with significance testing must buy and integrate a separate analytics or experimentation product.
  • Pricing by flag count punishes exactly the hygiene you want: the Pro tier caps at 100 flags, so teams that do not aggressively retire stale flags are pushed to the 325 dollar Smart tier for housekeeping reasons rather than growth.
  • The free tier allows only 2 environments, which does not cover the common development, staging and production split, so almost any real deployment starts on a paid plan.
  • It is a smaller vendor than the category incumbents, so enterprise procurement teams will find less depth in compliance attestations, contractual terms and reference architecture than LaunchDarkly offers.
  • Flag evaluation relies on SDK-side caching of a CDN-delivered config, which is fast but means propagation of a change is eventually consistent rather than instant, something to understand before relying on it as an emergency kill switch.

Sardine

  • Signal quality depends on the SDK being embedded in your own web and mobile clients, so fraud improvements become dependent on your app release cycle and any coverage gap is a blind spot.
  • Behavioural and device telemetry collection needs a documented lawful basis under GDPR, and EU privacy reviews frequently delay rollouts that were scoped as engineering work.
  • Pricing is per session or per active user, so a consumer product with many low value sessions pays in proportion to traffic rather than to fraud exposure.
  • As a younger private company it lacks the enforcement-tested audit history that a bank examiner expects, which makes it a harder sell inside a regulated bank than inside a fintech.
  • It is strongest on session-time signals and weaker as a system of record for long horizon AML typologies, so larger institutions end up running it alongside a traditional monitoring platform rather than instead of one.

Pricing, plan by plan

ConfigCat

Free
  • Forever FreeFree
    • 10 feature flags
    • 2 environments and 2 products
    • 2 segments
  • Pro$110/month
    • 100 feature flags
    • 3 environments and 3 products
    • Unlimited seats and MAUs
  • Smart$325/month
    • Unlimited feature flags
    • Unlimited environments, products and segments
    • Unlimited seats and MAUs
  • Enterprise$900/month
    • Everything in Smart
    • Enterprise support and controls
    • Unlimited everything on flag counts

Sardine

On request
  • Sardine$undefined/year
    • Priced per user session or per monthly active user
    • Annual contract with volume commitment
    • SDK for web, iOS and Android

Which should you pick?

Choose ConfigCat if

  • You need feature flags and configuration.
  • You want to start without paying.
  • You work on Web, API, iOS, Android, Node.js, .NET, Java, Python, Go.
  • You also want percentage rollouts.
ConfigCat review

Choose Sardine if

  • You need device intelligence.
  • You work on Web, iOS, Android.
  • You also want behaviour biometrics.
Sardine review

Questions people ask

Is ConfigCat or Sardine better?
Neither clearly leads. ConfigCat starts at Free and Sardine at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, ConfigCat or Sardine?
ConfigCat has a free tier; the other does not. Paid plans start at Free for ConfigCat and On request for Sardine.
Does ConfigCat or Sardine run on more platforms?
ConfigCat runs on Web, API, iOS, Android, Node.js, .NET, Java, Python, Go. Sardine runs on Web, iOS, Android.
Can I use ConfigCat for free?
Yes. ConfigCat has a free tier, so you can try it without paying. Sardine starts at On request.
What is ConfigCat best used for?
ConfigCat is most often used for a consumer or mobile app with millions of users where per-mau flag pricing would cost more than the flags are worth, a team that wants every engineer, product manager and support agent to have a login without paying per seat, decoupling deployment from release with percentage rollouts and a kill switch, without buying an experimentation platform, a small team that needs ten flags permanently and can run indefinitely on the free tier. Of those, a consumer or mobile app with millions of users where per-mau flag pricing would cost more than the flags are worth and a team that wants every engineer, product manager and support agent to have a login without paying per seat are not what Sardine is typically brought in for.
What can ConfigCat do that Sardine cannot?
ConfigCat covers Feature flags and configuration, Percentage rollouts, Targeting rules and segments, Unlimited seats. Sardine covers Device intelligence, Behaviour biometrics, Scam detection, Onboarding risk scoring.

Answered from the vendors’ own pages

ConfigCat: How is ConfigCat priced?

By feature flag, environment and product count. Seats, monthly active users and flag reads are unlimited on every plan.

Sardine: Does Sardine do document verification?

It focuses on device, behavioural and transaction signals, and integrates identity verification providers rather than being one. Treat it as complementary to a KYC vendor.

ConfigCat: Is the free tier usable?

For small projects yes, but at 10 flags and 2 environments it will not cover a dev, staging and production setup.

Sardine: What does it need from us to work?

An SDK in your web and mobile applications plus transaction feeds. Without the client side collector you lose the signals that differentiate it.

ConfigCat: Can it run A/B tests?

It can split traffic, but there is no statistics engine. You need a separate analytics tool to decide a winner.

Sardine: Is pricing published?

No. It is quoted, typically per session or per monthly active user with an annual volume commitment.

ConfigCat: How fast does a flag change take effect?

SDKs poll and cache, so changes propagate on the polling interval rather than instantly.

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