Stop fake accounts before they cost you.
Practical guides for SaaS and AI teams on signup fraud: free trial abuse, free-credit farming, disposable e-mail, Gmail aliases, headless browsers and multiple accounts.
How to prevent free trial abuse without blocking real users
Why people restart your free trial with new accounts, the signals that link those accounts together, and a decision flow that stops repeat trials while honest users keep a card-free trial.
How to stop free-credit abuse on an AI app
Free credits on an AI product cost real inference. How credit farms work, why per-account rate limits don't stop them, and where in the signup flow to decide.
How to block disposable email addresses at signup
Three ways to catch temporary e-mail addresses on your signup form, from a static blocklist to an API, with code, and the mistakes that block real users.
Gmail dots and plus aliases: how to catch duplicate signups
j.doe+7@gmail.com and jdoe@gmail.com are the same inbox. How Gmail addressing works, a normalization function in JavaScript and Python, and the edge cases that bite.
How to detect headless browsers and automation on your signup page
The browser signals that give away Puppeteer, Playwright and Selenium signups, why each one can be faked on its own, and how to combine them without blocking real people.
How to detect users with multiple accounts
Referral bonuses, free tiers and per-account limits reward people who open many accounts. The links that connect those accounts, and how to act on a cluster fairly.