CAPTCHA for SaaS that doesn't scare real prospects away
Fake signups, free-trial scraping, credential stuffing — stop them without making real prospects bounce at signup.
Threats this surface faces
Fake account farming on free tier
Bots create thousands of free-tier accounts to exhaust your trial credits, scrape your AI/API quotas, or stage for downstream abuse. CLV math goes sideways when 'new users' are 30% bots.
Credential stuffing on login
Leaked credentials from other breaches get sprayed at your login form. Even a 0.1% hit rate against a 100K credential list is 100 takeovers — and B2B SaaS takeovers correlate with data exfiltration, not just chargebacks.
Free-trial farming for AI / API credits
AI-focused SaaS is especially exposed: a fresh free-trial account is worth real dollars in inference quota. Bots automate signup → consume quota → discard, in a tight loop. CAPTCHA on signup turns this from profitable to expensive.
Payment-method test attacks
If you accept paid upgrades, the upgrade page becomes a card-testing target — especially for low-friction subscription flows. Same shape as ecommerce checkout abuse, smaller volume but real.
Where to place CAPTCHA in a SaaS signup funnel
You don't want it everywhere — that destroys trial conversion. You want it at the points bots actually hit.
- Signup / free-trial create
The single highest-value placement. One CAPTCHA here stops most fake-account farming, and adaptive difficulty keeps real prospects invisible.
- Login & SSO password reset
Credential-stuffing defense without locking real users out. Pairs well with rate limiting.
- Paid plan upgrade
Card-testing protection on the payment flow. Light placement — most upgrades come from logged-in users.
- Team invite acceptance
Stops mass-invite spam from a compromised account. Often forgotten.
- API key creation
Cap a compromised session from spawning unlimited keys. Defense-in-depth, not first-line.
- Help-desk / contact form
Stops spam tickets that bury real support. Cheap insurance.
Frequently asked questions
Won't a CAPTCHA on signup hurt our trial conversion?
Adaptive CAPTCHA is designed not to: most real prospects see a single click or nothing visible at all. The 1–3% who get a visible challenge are also the highest-risk traffic. Side-by-side measurements typically show flat or slightly improved trial conversion vs. having no CAPTCHA (because bot signups dilute the funnel).
Does CaptchaLa work with our auth provider (Auth0, Clerk, Supabase, Firebase)?
Yes — CaptchaLa runs in front of any auth provider. You inject the widget into the signup form (your UI), validate the token server-side before calling the provider's signup API. The pattern is documented for each major provider in our docs.
How do we tell signups from real prospects vs. bots?
CaptchaLa returns a risk score with each verification. You can pass that score along to your downstream signup tracking, so analytics distinguishes 'high-trust signup' from 'verified but elevated risk' and you can size cohorts honestly.
What about our enterprise customers' SSO flows?
SSO flows usually don't need a CAPTCHA — the identity is already established. Apply CAPTCHA on email/password fallback flows, on password reset, and on the initial SSO connection setup if that involves a self-serve step.