Use multi-factor authentication (MFA) on all important accounts to prevent hackers from logging in even if they have your password.
One of the most effective ways these tools "work" for you is through proactive notification.
Understanding How Data Breach Checkers Like "Have I Been Pwned" Work
Many breaches are added after companies publicly acknowledge a security incident and the resulting data becomes accessible to researchers. 2. The Mechanics of the Search
To maintain privacy, many of these services use "k-Anonymity." This means when you check a password or email, only a portion of its cryptographic hash is sent to the server, ensuring the service itself never actually sees your full, plain-text credentials.
The core of these platforms is a database containing billions of records from hundreds of known data breaches.
Immediately update the password for the breached service and any other account where you used the same password.