All use cases

Free Trial Account Abuse Prevention

Free trial abuse looks like growth until you see the bill. The same person signs up again and again with throwaway emails and a VPN. One API call at signup lets Fidro spot the pattern and stop it, without punishing your real users.

What is Fidro?

Fidro is a fraud detection API for developers. One call checks the email, the IP and the network, remembers what it has seen before, and tells your code to allow, challenge or block, so you stop fake signups and stolen cards without building your own scoring. The free plan covers 200 validations a month, no credit card.

The problem

Serial abusers create account after account with disposable emails and VPNs, so your free tier never runs out for them. It costs real money in servers and support, brings in nothing, and makes your conversion numbers look worse than they are.

How Fidro fixes it

Fidro catches the throwaway email and the masked IP, and remembers what it has seen: sam+1@, s.a.m@ and sam42@ count as one pattern, and the fifth signup from one IP this hour gets challenged before the account exists. Real users sail straight through.

What you get

Pattern memory

Plus-tags, dots and trailing digits are stripped before matching, and signups are counted per IP and network, so repeat accounts stand out.

VPN and proxy detection

Spot signups hiding their real location to get around your account limits.

Your own blocklists

Block the domains, emails and IPs you've already caught abusing your service. Starter plan and up.

50K+
Disposable domains
Real-time
Detection speed
Every plan
Memory included

Keep exploring

Try the free checkers on a real address, read every field in the docs, or see how Fidro compares.

All features API documentation Free email checker Free IP checker Compare Fidro

Frequently Asked Questions

How do I stop users from abusing my free plan?
Check every signup with Fidro. It flags disposable emails, VPNs and proxies, and remembers recent signups, so the same person coming back with a new alias or from the same IP gets challenged before the account exists.
How do people abuse free tiers?
Mostly by signing up again and again: new disposable emails, plus-tag aliases of the same address, a VPN to look like someone else, sometimes a script doing it for them. Fidro catches each of these through email checks, IP intelligence and its memory of recent signups.
Can I build custom blocklists with Fidro?
Yes, on the Starter plan and up. Add the domains, email addresses and IPs you've caught abusing your service, and Fidro checks them on every call, alongside its built-in disposable email detection.
Will Fidro block legitimate users?
Fidro gives you a score and a recommendation, not a blunt yes or no. You decide what happens: send borderline signups to email confirmation or review, and keep outright blocks for the clear cases.

Start catching bad signups in the next 5 minutes

Create your account, grab your API key, and send your first request. Free plan with 200 validations/month. No credit card. Cancel anytime.

Start for free Read the docs