Have I Been Pwned is the standard first stop for checking whether an email address has shown up in known breaches. Key features include:

  • Search an email address against a large breach corpus
  • Detailed summaries of breached services and exposed data types
  • Includes the widely used Pwned Passwords service
  • Useful for triaging account exposure after breach news
  • Best paired with unique passwords, password manager use, and MFA