https://howsecureismypassword.net/

This resource tests how long it would take to crack a password. The teacher could use this resource to test common passwords that the students might share in a class brainstorm of ‘common passwords’. It is important that the teacher instructs students to not share their own passwords during this activity. This could lead into teaching segments on why it is important to not use a common password and how students could develop strong passwords in the future.