SecuryBlackIs my password breached?
Check without your password ever leaving your browser.
We compute the SHA-1 hash of your password in your own browser and send only the first 5 characters of that hash to the public Have I Been Pwned API (k-anonymity). Those 5 characters can't be used to reconstruct your password or identify which one you were checking among the thousands sharing that same prefix. Your full password and the full hash never leave your browser.
How does password breach checking work?
Data breaches expose billions of credentials online. Attackers use automated tools to attempt credential stuffing attacks against multiple websites.
To protect your privacy, we implement mathematical k-Anonymity with Pwned Passwords: your password never leaves your browser. Only the first 5 characters of its SHA-1 hash are queried.
Password Security FAQs
Is it safe to test my password here?
Yes, completely safe. SecuryBlack never sees your actual password or full hash. k-Anonymity guarantees privacy mathematically.
What should I do if my password is leaked?
Change it immediately across all services where you reused it, and enable two-factor authentication (2FA) or passkeys.
A password is one layer. You need more.
Two-factor authentication (2FA) protects you even if the password leaks. Learn how to set it up on your server.
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