If you run a bank, a fintech app, or anything that moves other people's money, you have to solve a problem that's genuinely hard: telling a legitimate customer apart from someone trying to defraud you, in the split second before you approve a transaction — not days later when the money's already gone and a chargeback lands on your desk. This is the job of fraud-detection and anti-money-laundering (AML) software, and it usually comes in one of two flavors: a system that watches and scores transactions automatically in the background, or a system that gives your own risk team the controls to write and adjust the rules themselves.
Sardine and Unit21 are two well-known platforms that represent these two approaches — and notably, each lists the other as a direct alternative, so this is a real head-to-head, not an apples-to-oranges comparison.
The short version
Sardine scores the risk of a payment automatically, in real time, using device fingerprinting, behavioral signals and identity checks — you get a risk score, and a fraud-intelligence network effect from its other customers. Unit21 instead hands your risk and compliance team a no-code rule builder, so they can write and tweak detection logic themselves without waiting on engineering, plus the case-investigation and regulatory-filing tools (like Suspicious Activity Reports) that a bank or fintech legally needs afterward. Pick Sardine if you want automated, real-time scoring across a broad range of payment rails. Pick Unit21 if your risk team needs to own and adjust the rules themselves, and if you operate in the US where its SAR/STR/CTR filing tooling directly maps to your regulatory obligations.
Sardine: real-time scoring, in the moment
Sardine scores a payment's fraud risk while it's happening, by checking the device, behavioral and identity signals behind it, across a broad range of payment rails. It consolidates fraud detection, KYC/KYB identity verification and sanctions screening into one platform, and its fraud-intelligence consortium — built from patterns seen across its 450+ enterprise customers, including major fintech infrastructure players like Nubank and Intuit — creates a network effect that a single company building its own rules from scratch can't easily replicate.
- Best for: banks, fintechs and payment processors that want automated, real-time risk scoring baked into the transaction flow itself.
- Watch out for: pricing is fully custom enterprise (no public numbers), and some of its headline scale claims — like sub-100ms latency — are widely cited but weren't independently confirmed on its own current site, so they're worth a direct question in a sales call.
Unit21: no-code rules your risk team controls
Unit21 is built around the idea that the people who understand fraud and compliance risk best — your risk and compliance team — shouldn't need an engineer to change a detection rule. Its no-code rule builder lets them adjust detection logic directly, and the platform combines that with case investigation tools and automated regulatory filing. That last part is a genuinely significant claim: Unit21 reports handling roughly 5% of all US Suspicious Activity Reports (SARs) filed, which is a strong signal of real production usage at scale, backed by a fraud-data consortium covering 80M+ US adults.
- Best for: fintechs, digital banks, payment processors and crypto platforms — especially US-based ones, since its automated filing tools (SARs, STRs, CTRs) are built around US regulatory requirements.
- Watch out for: like Sardine, pricing is custom enterprise sales with no public numbers, and its scale/efficiency figures are self-reported — again, worth asking about methodology directly.
| Criteria | Sardine | Unit21 |
|---|---|---|
| Core approach | Automated real-time risk scoring during the payment | No-code rule builder your own team configures |
| Includes | Fraud scoring, KYC/KYB, sanctions screening | Detection, case investigation, automated regulatory filing |
| Geographic focus | Worldwide | Primarily United States (SAR/STR/CTR filing) |
| Notable scale signal | 450+ enterprise customers, fraud-intelligence consortium | ~5% of all US SARs filed, 80M+ adults in fraud-data consortium |
| Pricing | Custom enterprise, no public pricing | Custom enterprise, no public pricing |
| Best for | Automated scoring across broad payment rails | Risk teams who want to own and adjust rules themselves |
Neither platform publishes pricing, so a real evaluation means getting both on a call and asking pointed questions about the latency and scale numbers each one advertises. But the underlying choice is clear enough on paper: Sardine leans toward "let the system score it automatically," Unit21 leans toward "let our risk team configure exactly how it gets scored." If your compliance team already has strong domain expertise and wants direct control, that tips toward Unit21. If you'd rather lean on an existing fraud-intelligence network and automated scoring, that tips toward Sardine.