Free fraud check tools
Is this email real? Is that IP hiding behind a VPN? Paste it in and get an answer in seconds. Free, no signup.
Email Validation Tool
Find out if an address is real, a typo, or a throwaway inbox from a disposable email provider.
Bulk Email Validator
Paste up to 10 addresses and see which ones are invalid or disposable, all in one go.
IP Address Checker
See where an IP really is, who runs it, and whether it shows up on threat lists.
VPN & Proxy Detector
Find out if a visitor is hiding behind a VPN, a proxy, Tor or a datacenter server.
Domain Reputation Checker
Check whether a domain can receive email and whether it belongs to a disposable provider.
Quick answers for suspicious signups.
Answers in seconds
Paste it in, get a verdict. No queue, no report to wait for.
No account needed
Every tool works without signing up. Use it on the next odd-looking signup.
Lists that stay fresh
Disposable, proxy, Tor and flagged-IP lists refresh every day.
API
Run the same checks on every signup.
Every check here is in Fidro's API, plus the part a one-off lookup can't do: it remembers who it has seen and answers allow, challenge or block for each signup.
Browse our disposable email database, compare Fidro to alternatives, or read the blog.
curl -X POST https://fidro.io/api/validate \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{"email": "user@example.com"}'Frequently Asked Questions
Are these tools free?
Yes. Every tool works without signing up, with a fair daily limit on each one. If you want the checks inside your own signup flow, the API's free plan includes 200 validations a month.
How do these tools work?
Each tool checks what you paste against Fidro's own lists: known VPN ranges, proxy services, Tor exit nodes, datacenter networks, disposable email domains and IPs flagged for abuse. You get the answer straight away.
Can I use these tools via API?
Yes. Every check here is in Fidro's REST API too, plus memory of who you've already seen. Get a free API key and send one request from your signup handler.
How often is the data updated?
Disposable email domains, proxy lists, Tor exit nodes and flagged IPs refresh daily. VPN, datacenter and high-risk ISP lists refresh weekly.
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.