About StuffingGuard
In a world of data breaches, checking your security shouldn't require giving up more of your data.
What is StuffingGuard?
StuffingGuard is a free, open-source web tool that helps you check if your email address or password has been exposed in known data breaches.
When hackers compromise websites, databases, or services, they often leak or sell millions of stolen credentials online. These leaked credentials are then used in credential stuffing attacks—automated attempts to log into your other accounts using the same email and password combination.
StuffingGuard checks your credentials against databases of known breaches to tell you:
- For emails: Which data breaches (if any) have exposed your email address
- For passwords: Whether your password has appeared in any known breach databases
If your credentials have been compromised, you'll know immediately—and can take action by changing your passwords, enabling two-factor authentication, or monitoring your accounts for suspicious activity.
Pro Tip: Creating a New Password?
You can also use StuffingGuard before setting a new password. Check if your desired password has already been exposed in previous breaches. If it has, choose a different one—even strong passwords aren't safe if they've already been stolen and published online.
Peace of Mind, Without the Corporate Bloat
StuffingGuard is a tool built for people, not for profit or data collection. We believe security tools should protect you, not exploit your data. No ads, no subscriptions, no hidden agendas—just a simple, powerful tool that does one thing well: tells you if you're safe.
The “Ghost” Promise
Privacy First
Most tools ask you to trust them. StuffingGuard asks you not to.
“We don't know who you are, and we don't want to.”
Unlike other services that require an account or email signup just to run a check, StuffingGuard is stateless. We do not store, log, or even see your full data. You enter, you check, you leave. No footprints left behind.
The “Glass Kitchen”
100% Open Source Transparency
Trust is earned through visibility.
“Don't trust our words, trust our code.”
Security tools shouldn't be black boxes. StuffingGuard is fully open-source, meaning our entire codebase is public on GitHub. Security researchers and developers can inspect exactly how your data is handled, ensuring there are no hidden backdoors or trackers.
Community Verified. Publicly Auditable. Zero Secrets.
Math, Not Magic
K-Anonymity Hashing
We use k-anonymity to protect your privacy. When you check a password, your browser converts it into a cryptographic code (hash) and sends only the first 5 characters to the database.
We never send or see your actual password—it never leaves your device. This technique ensures that even if someone intercepted the request, they couldn't reverse-engineer your password.
Your House, Your Rules
Easy to Self-Host
“Don't trust us? Run it yourself.”
Paranoid about privacy? We get it. Because StuffingGuard is a lightweight Next.js app, you can clone our repository and run the tool entirely on your own local machine.
You don't even have to trust our website—you can run your own instance on localhost. Complete control, complete privacy.
Just the Answer You Need
No Bloat, No Ads, No Upsells
We aren't trying to sell you a subscription or show you ads. We are a single-purpose tool designed to do one thing well: tell you if you're safe.
Clean. Fast. Free. Forever.
Why StuffingGuard?
✓ Stateless & Private
No accounts, no logs, no tracking. Your searches are ephemeral.
✓ Client-Side Hashing
Your password never leaves your browser in plain text.
✓ Community Verified
100% Open Source code that anyone can audit on GitHub.
✓ Run It Yourself
Don't trust us? Download and run it locally on localhost.
Security Without Surveillance
StuffingGuard proves that you don't need to sacrifice privacy for security. We protect your data by never collecting it in the first place.