Breach Pattern Checker
Analyse your password for patterns that are disproportionately common in known data breaches. Detects keyboard walks, date patterns, leet-speak substitutions, dictionary fragments, repeated sequences, and 15+ other breach-risk patterns — all locally in your browser. No API calls. Your password never leaves this page.
| Pattern Category | Example | Breach Risk |
|---|---|---|
| Top common passwords | password, 123456, qwerty | Critical |
| Keyboard walk | qwerty, asdfgh, 1qaz2wsx | Critical |
| All-digit sequence | 123456, 654321 | High |
| Repeated block | abcabc, 123123 | High |
| Leet substitution | p@ssw0rd, s3cur1ty | High |
| Year suffix/prefix | password2024, 1988secret | Medium |
| Date pattern | 01011990, 12/25/1985 | Medium |
| Dictionary word base | correct123, sunshine! | Medium |
| Char class padding | Password1!, Secret99@ | Medium |
| All same character | aaaaaaa, 1111111 | Critical |
Frequently Asked Questions
Does this tool check against a breach database?
No. It analyses your password for patterns commonly seen in breached datasets. Your password is never transmitted anywhere.
What patterns does the checker detect?
15+ categories: keyboard walks (qwerty, 12345), leet-speak (p@ssw0rd), year patterns, repeated characters, common words, palindromes, sequential runs, and more.
Is my password sent to any server?
No. All analysis runs locally in your browser. Your password never leaves your device.
What should I do if my password matches patterns?
Replace it with a randomly generated password using our Password Generator, which produces patterns undetectable by any rule-based cracking tool.