Castle
Castle protects user accounts and transactions from takeover, fraudulent signups and abusive usage with a developer-first API. It offers risk scoring, device fingerprinting, webhooks and policies, and is popular with SaaS companies like Sho
Active Fraud & Risk Management
Our Verdict
The right pick for SaaS teams that want ATO and signup protection via API without an enterprise contract.
Pros
- Developer-first API with clear docs and webhooks
- Policies let you codify risk rules without retraining
- Fast integration for SaaS login and signup flows
- Reasonable pricing for mid-market SaaS
Cons
- Weaker on payment fraud vs PSP-native tools
- Smaller data network than LexisNexis or Ekata
- Requires you to tune rules and thresholds yourself
- Limited out-of-box bot mitigation vs DataDome
Best for: B2B and B2C SaaS protecting logins, signups and workspace abuse with a small risk team.
Not for: Payment-first merchants or bot-heavy retail needing dedicated WAF-layer mitigation.
When to Use Castle
Good fit if you need
- Risk scoring for new user signup abuse prevention
- Account takeover detection via device fingerprint changes
- SaaS platform abuse policy enforcement via webhooks
- Fraud signal enrichment for Shopify checkout flows
- Adaptive MFA trigger based on real-time risk score
Lock-in Assessment
Medium 3/5
Lock-in Score 3/5
Pricing
Price wrong?Castle Pricing
- Pricing Model
- freemium
- Free Tier
- Yes
- Entry Price
- —
- Enterprise Available
- No
- Transparency Score
- —
Beta — estimates may differ from actual pricing
1,000
1001K10K100K1M
Estimated Monthly Cost
$25
Estimated Annual Cost
$300
Estimates are approximate and may not reflect current pricing. Always check the official pricing page.
Community Discussion
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