How to Force Strong Password on Users in WordPress

We will use the plugin Force Strong Passwords. This plugin duplicates the WordPress JavaScript password strength check in PHP, and forces users with executive powers to use a strong password.

So basically any user that has the capability to publish posts, upload files, or edit published posts must have a strong password. This means all user roles except for Contributor and Subscriber.

All you have to do is install and activate the plugin. It will take care of the rest.