Softwr

Cybersecurity · head to head

Clerk vs Sardine

Clerk logo

Clerk

Cybersecurity

Drop-in user authentication and management for developers

From
Free
Rated
-
Full reviewWebsite
Sardine logo

Sardine

Cybersecurity

Device intelligence and behaviour biometrics for fraud and compliance

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only Clerk has a free tier, so it costs nothing to try first.
  • Each has a real cost: Clerk pricing scales with monthly retained users, which can grow expensive quickly for consumer apps with large user bases.; 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: Clerk covers Prebuilt UI components, Sardine covers Device intelligence.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Clerk and Sardine actually diverge.

Attributes where Clerk and Sardine differ
AttributeClerkSardine
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
Platformsweb, ios, android, apiWeb, iOS, Android

Identical on both: user rating (Not yet rated), category (Cybersecurity).

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 Clerk

  • Prebuilt UI components
  • Organization management
  • Multi-factor authentication
  • Social sign-on
  • Billing
  • Enterprise connections

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.

Clerk

  • Adding sign-in and user profiles to a web or mobile app quicklynot Sardine
  • B2B SaaS apps needing organizations and role-based accessnot Sardine
  • Startups wanting prebuilt UI instead of building auth in-housenot Sardine
  • Apps needing MFA and fraud detection out of the boxnot Sardine

Sardine

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

Where each one falls short

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

Clerk

  • Pricing scales with monthly retained users, which can grow expensive quickly for consumer apps with large user bases.
  • Enterprise SSO connections beyond the first are billed as add-ons, adding cost for larger organizations.
  • The Business tier's extra dashboard seats cost $20/month each, which adds up for larger teams.
  • Enterprise-tier features like the 99.99% uptime SLA require annual contracts rather than flexible monthly billing.

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

Clerk

Free
  • HobbyFree
    • 50,000 MRU limit per app
    • Up to 3 dashboard seats
    • Unlimited applications
  • Pro$25/month
    • 50,000 MRUs included, $0.02/MRU overage
    • Up to 3 dashboard seats
    • 1 Enterprise Connection included
  • Business$300/month
    • 50,000 MRUs included with volume pricing
    • 10 dashboard seats included
    • SOC2 report and priority support
  • Enterprise$undefined/month
    • Custom pricing, annual billing
    • 99.99% uptime SLA
    • HIPAA available, dedicated Slack channel

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 Clerk if

  • You need prebuilt ui components.
  • You want to start without paying.
  • You work on web, ios, android, api.
  • You also want organization management.
Clerk 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 Clerk or Sardine better?
Neither clearly leads. Clerk 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, Clerk or Sardine?
Clerk has a free tier; the other does not. Paid plans start at Free for Clerk and On request for Sardine.
Does Clerk or Sardine run on more platforms?
Clerk runs on web, ios, android, api. Sardine runs on Web, iOS, Android.
Can I use Clerk for free?
Yes. Clerk has a free tier, so you can try it without paying. Sardine starts at On request.
What is Clerk best used for?
Clerk is most often used for adding sign-in and user profiles to a web or mobile app quickly, b2b saas apps needing organizations and role-based access, startups wanting prebuilt ui instead of building auth in-house, apps needing mfa and fraud detection out of the box. Of those, adding sign-in and user profiles to a web or mobile app quickly and b2b saas apps needing organizations and role-based access are not what Sardine is typically brought in for.
What can Clerk do that Sardine cannot?
Clerk covers Prebuilt UI components, Organization management, Multi-factor authentication, Social sign-on. Sardine covers Device intelligence, Behaviour biometrics, Scam detection, Onboarding risk scoring.

Answered from the vendors’ own pages

Clerk: What does Clerk cost?

Clerk's Hobby plan is free with a 50,000 MRU limit; Pro is $25/month ($20/month billed annually), Business is $300/month ($250 annually), and Enterprise uses custom annual pricing.

Source
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.

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

Yes, the Hobby plan is free with a 50,000 monthly retained user (MRU) limit per app, up to 3 dashboard seats, and unlimited applications, with no credit card required.

Source
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.

Clerk: How is usage metered?

Clerk meters by monthly retained users (MRUs) — users who return to the app at least a day after signing up — with overage billed at $0.02 per MRU beyond the included 50,000 on paid plans.

Source
Sardine: Is pricing published?

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

Share

Related pages

More on Clerk

More on Sardine

Keep looking

Other head to heads