have i been pwned? - Check if your account has been compromised in a data breach
How Secure Is My Password? - A tool for assessing your password strength
DeHashed - DeHashed is the largest & fastest data breach search engine.
1Password - 1Password can create strong, unique passwords for you, remember them, and restore them, all directly in your web browser.
LeakCheck - Data breach search engine, low price starting from $10/mo, one email address for free, unlimited API, 7B+ entries
BreachDirectory.org - BreachDirectory.org allows you to search through all public data breaches to make sure your emails, usernames, passwords, and domains haven't been compromised.