HOW & WHY
Just start with typing the name of the website you looking for and suggestions will pop up, select the right one and you will get to the page where you will see the requirement for that website.If there isn't coming up any suggestions that are the one your looking for or you just want to suggest a site, then you can do that on the suggestion tab on the right. Type the website you suggest and if you what you can type your email and if so you will get an email when the website is added to our database.
Many people have unfortunately the same password on many different websites and sometimes some websites have a strong password requirements and then most people add a symbol or a number. So on passrequirements.com you can search for the password requirements and then know what symbol, number or what it is that you are missing.