Have I Been Pwned (HIBP)

Have I Been Pwned (HIBP) is a free service created by security researcher Troy Hunt that aggregates data from publicly known breaches. Users can enter their email address to see if it appears in any breach database, and the service provides details about which breaches affected them.

HIBP also offers a password checking service (Pwned Passwords) with over 800 million compromised passwords. Many password managers integrate with this API to alert users when a stored password has been found in a breach.

For teams, regularly checking HIBP (or using a password manager that does so automatically) is a simple but effective way to identify compromised credentials before attackers exploit them.