Trusted password security
Your passwords, uncrackable.
Generate strong passwords and PINs, see if yours has leaked in a breach, and learn exactly what to avoid — all in your browser. Nothing is stored, nothing is sent.
100% client-side · zero-knowledge · open methodology
The toolkit
Everything you need to lock things down.
Four focused tools. No account, no tracking, no nonsense.
Password & PIN generator
Cryptographically-random passwords and PINs with a live strength read-out.
OpenBreach & strength checker
Test any password or PIN for strength and whether it’s turned up in a breach.
OpenCommon passwords to avoid
The most-breached passwords by length — see what attackers try first.
OpenStrong, memorable examples
A hundred passwords that are easy to remember and hard to crack.
OpenHow it works
Strong in three taps.
Generate
Pick a length and character types. We draw from your device’s secure randomness — never a server.
Check
Confirm it’s strong and that it hasn’t appeared in any known breach corpus.
Save it safely
Copy it into your password manager. We keep nothing — close the tab and it’s gone.
Why CheckPasscode
Security you can actually verify.
Zero-knowledge by design
Everything runs in your browser. Your passwords never touch our servers — there’s nothing for us to lose.
True randomness
Keys come from the Web Crypto API with unbiased sampling — not a predictable pseudo-random seed.
Real breach intelligence
Checked against 17.8B exposed credentials, refreshed as new corpora are disclosed.
Works offline
Install it once and the whole toolkit keeps working with no connection — a true progressive web app.
Don’t guess — know
Has your password already leaked?
Most people reuse a password that’s already in a breach list. Check yours in seconds — privately, right here.
Run a free checkLoved by careful people
Quietly keeping accounts safe.
“The only generator I trust — I can see it never phones home. It’s become the first tab I open on a new device.”
“Finally a strength checker that explains *why*. I moved my whole family onto it in an afternoon.”
“Clean, fast, and it works offline on my phone. The memorable-examples page alone is worth it.”
Questions
The details, answered.
Do you store or see my passwords?
No. Every tool runs entirely in your browser. Passwords are never transmitted, logged, or stored — there is nothing on our side to leak.
How are passwords generated?
With the browser’s Web Crypto API using unbiased rejection sampling, so every character is uniformly random — not a guessable pseudo-random sequence.
How does the breach check stay private?
Matching happens locally against a compiled index of exposed credentials. Your input never leaves the page.
Is it really free?
The toolkit is free to use. We don’t run ads or sell data — the product is the point.
Can I use it offline?
Yes. Add it to your home screen and the whole toolkit keeps working with no connection.
Create a password worth trusting.
It takes about three seconds. Your future self will thank you.
Open the generator