xonPlus is described as 'Every day, new breaches expose millions of credentials, and that puts your organization at risk of account takeovers and ransomware attacks. xonPlus changes the game by watching your email addresses and domains against fresh breach data, so you know the moment your data appears' and is an website in the development category. There are more than 25 alternatives to xonPlus, not only websites but also apps for a variety of platforms, including Windows, Linux, Self-Hosted and Mac apps. The best xonPlus alternative is Have I Been Pwned, which is free. Other great sites and apps similar to xonPlus are Data Breach Observatory, Mozilla Monitor, Intelligence X and LeakCheck.