Using iCloud Keychain, Apple's Safari browser stores and syncs all the passwords you use for different websites and apps through ‌iCloud‌. And in iOS 14 and later, Apple provides security recommendations that warn you if a password you're using is putting your accounts at risk.

Safari securely monitors your saved passwords using strong cryptographic techniques, and regularly checks derivations of your passwords against a list of breached passwords in a secure and private way that doesn’t reveal your password information to anyone, including Apple. If Safari discovers a breach, it will alert you and can automatically generate a new secure password.

Examples of security alerts that you might see include:

To check your passwords for security recommendations generated by Safari in iOS, simply follow the steps below.

If you're using Safari on Mac, you can find the same security recommendations available in the Passwords tab in Safari -> Preferences....