Use single password to create unique passwords for many websites.
Today we hear almost everyday about user data leaks. If you're using the same password on many websites you are at risk of being hacked. Intruder can buy your credentials and use them to takeover your identity or any other valuable possessions.
Using MasterPassword.org you are able to create secure, unique passwords for many pages using single "Master password". If someone steals password you are using on site X he still won't be able to guess passwords for other websites.
Application doesn't know anything about you (login, name etc.) and doesn't send anything you input over the Internet. Password is generated in your browser using strong cryptography.
Above guarantees your credentials will be safe.
In order to create new password:
Remember that the final password is unique to any domain / master password you will enter - in case you will make any typo different password will be generated.
If you want to be sure if you have entered correct "Master password" check the graphic sign that is presented next to the password. It will be different for almost any password you'll type.
Try to type strong password as your Master password. Next to the input you'll find a hint box indicating if your Master password is considered to be strong. Read also: How to create strong password?
Avoid saving anywhere your Master password. To easily store your generated passwords use one of Password Managers.