If your website Google traffic suddenly becomes zero or goes down sharply then it may be possible that it has been penalized by Google. You need to analyze Google penalty. Here are given some effective ways to check about Google Webmaster penalty.
Type your full domain URL in Google Search
First type and search your website full URL without http:// i.e “yourdomain.com”. If Google search shows only one result ( homepage) then possibly it is a penalty or if it shows some other results then there should be no penalty.
Type only website name or domain keyword ( without TLD such as .com,.net etc)
If after typing domain keyword only i.e. typing “yourdomain” instead of “yourdomain.com”, Google search shows no result then it should be a penalty but if it shows one or more than one result then there should be no penalty.
Typing full website address i.e including http://
If Google search shows only single result (homepage) by searching full website URL i.e” “http://yourdomain.com” then possibly it may be a severe Google penalization.
SEO-Move Online Penalty checker tool
SEO Move is an excellent tool to check Google penalization. Just got to SEO Move website and enter your domain to check penalty. By following these 4 steps you can easily confirm about your domain Google Webmaster Penalty if any.