Find out if your password appears in a known data breach. Only the first 5 characters of its SHA-1 hash are ever sent.
Uses Have I Been Pwned's k-anonymity API — your full password is never transmitted.
Even a long, complex password is useless once it appears in a public data breach — credential-stuffing bots will try it against every site they can reach. This tool checks your password against the Have I Been Pwned dataset of half a billion breached passwords, using k-anonymity: only the first five characters of your password's SHA-1 hash are ever sent over the network, so the full password never leaves your device.
Open the page, enter the input you want to check, and the result appears immediately above — there is nothing to install, no account to create, and no popup to dismiss. Every Toolzer utility is designed to give you the answer on the first screen and let you copy or share it in one click. If the result looks unexpected, run the test a second time: transient network conditions, browser extensions, and corporate proxies can all affect single-shot measurements, and a fresh run usually confirms whether the issue is real or a one-off blip.
Every tool on Toolzer is built to work on desktop and mobile, including the latest versions of Chrome, Edge, Firefox, Safari, and Brave. Results are rendered directly in your browser whenever possible, so the page stays responsive even on slow connections. When a server lookup is required — for example to query public DNS, WHOIS, or geolocation databases — the request is proxied through Toolzer's edge so the third-party service never sees your IP address.
Toolzer is a privacy-first toolbox: the page is served as a static, minified bundle with long-lived cache headers, so repeat visits are essentially free for both you and our servers. Inputs you type — text to format, passwords to generate, URLs to inspect — stay on your device unless an explicit server lookup is required. We do not sell data, we do not run third-party advertising trackers, and we do not require an account to use any tool on the site.
Bookmark this page and pair it with the other utilities listed below; together they cover most of the day-to-day SEO, networking, security, and developer tasks that would otherwise need three or four separate apps. If you spot a result you cannot explain, the FAQ underneath answers the most common questions about how the underlying measurement works and where its limits are.
Yes. We hash your password locally with SHA-1, send only the first 5 hex characters, and compare the rest in your browser. No site (including ours) ever sees the password or its full hash.
It's how many times the password has appeared across all known breaches in the HIBP dataset. Even a single appearance means it's on attackers' wordlists.
Yes — and everywhere you've reused it. Treat each breach as confirmation the password is no longer secret.
The Pwned Passwords API was designed around SHA-1 for compatibility with leaked hash dumps. K-anonymity makes the choice of hash irrelevant to privacy.
No. Every utility on Toolzer is free, anonymous, and works in any modern browser without registration. You will never see a paywall or a forced sign-up flow — the goal is to give you the answer on the first screen and let you move on.
Yes. Whenever the tool can produce an answer entirely in the browser — password generation, JSON formatting, regex testing, hashing, text counting — the data never leaves your device. When a server lookup is unavoidable (DNS, WHOIS, geolocation), the request is proxied through Toolzer's edge so the upstream service never sees your real IP address.
Yes. The interface is fully responsive and works on iOS Safari, Android Chrome, Samsung Internet, and every other up-to-date mobile browser. You can pin the page to your home screen for one-tap access.
Yes. Every Toolzer page has a clean, permanent URL you can bookmark, share, or paste into a ticket. Results are generated client-side on each visit, so the link always shows fresh data instead of a stale screenshot.
