About this email breach checker
Data breaches are the raw material of credential stuffing, account takeover and targeted phishing. This checker uses Have I Been Pwned's public breach database to tell you whether the domain in your email address has been involved in a known breach, and links directly to HIBP's per-account lookup so you can check the exact mailbox.
How to use Email Breach Checker
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.
Privacy & how this tool works
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.