GTmetrix tells you a lot about your website performance.
This excellent, web based and totally free tool gives you insight on how well your site loads and provides actionable recommendations on how to optimize it. This tool is a gem for those who are looking to optimize their sites. Instead of downloading the YSlow extension, or going to Google Webmaster Tools to get Google Page Speed score, you can simply do it all through GTMetrix dashboard.
Check out this example report:
As you can see in the report breakdown, it shows all the things you need to work on based on the priority level. It provides both, Google Page Speed, and YSlow from Yahoo speed grades. The best part is when you click on the tab, it will give you exact list of items that need to be worked on and an explanation on how to do it. Each tab also has a “What does this mean?” info window. If you click on that, it will tell you in full details what each of the items mean as well as the link with more resources.
What are your thoughts on GTMetrix? Have you been using it for your sites? Let me know in the comments.