Google Pagespeed Insights Checker is an advanced free SEO tool.
Google Page Speed Info Checker will check your webpage speed score analysis, your page code and give you the most useful page optimization suggestions. This tool is one of the most important Google ranking factors, and every webmaster should focus on improving the speed of their site.
According to surveys, over 45% of people expect a web page to load in less than 2 seconds, and 40% will leave a web page if it takes longer than 3 seconds to load! It, therefore, becomes very important for each webmaster to reduce the loading time of his site. Google thinks that the speed of the site is the most important.
Google introduced its Pagespeed Insights tool in 2011 to provide recommended metrics and improvements for slow loading pages.