Email Breach Checker: Has Your Email Been in a Data Breach?

What Is a Data Breach?

A data breach occurs when hackers gain unauthorised access to a company's database and steal user records — typically containing email addresses, passwords, names, and sometimes payment details. These stolen records are then sold on dark web marketplaces or published publicly.

Check if your email has been exposed: Email Breach Checker →

How Many Breaches Has Your Email Appeared In?

The average person's email address appears in 3–5 known data breaches. Major breaches at LinkedIn (700 million records), Adobe (153 million), Yahoo (3 billion) and many others mean that almost everyone has been affected by at least one breach.

Is It Safe to Check Your Email?

Our breach checker uses k-anonymity — the same privacy-preserving method used by HaveIBeenPwned. Here is how it works:

1. Your browser hashes your email address using SHA-1
2. Only the first 5 characters of the hash are sent to the API
3. The API returns all breach records matching those 5 characters
4. Your browser checks locally if your full hash is in the results

Your actual email address is never transmitted to any server. Only a 5-character hash prefix leaves your browser.

What to Do If Your Email Is in a Breach

1. Change your password immediately on the affected service
2. Change the same password everywhere else you used it — password reuse is the biggest risk
3. Enable two-factor authentication on the affected account and ideally all important accounts
4. Watch for phishing emails that reference the breached service — attackers use breach data for targeted phishing
5. Generate a new strong password using our Password Generator

How to Prevent Future Breaches Affecting You

• Use a unique password for every site — a password manager makes this practical
• Use a strong, random password — our Password Generator creates cryptographically random passwords
• Enable 2FA everywhere — even if your password is stolen, 2FA blocks access
• Use a disposable email for low-trust signups — check with our Disposable Email Checker
• Monitor regularly — check your email every few months as new breaches are discovered constantly

Biggest Data Breaches Ever

Related Tools

• Password Generator — Create a strong replacement password
• Disposable Email Checker — Detect throwaway email addresses
• IP Blacklist Checker — Check if your IP is on spam lists