With Google's "Mobile First" push, more now than ever it is important to have a fast optimized website. Here is a list of some great tools to help you assess the performance of your website and know where you can improve.
AMP Test – This tools test a website or webpage for AMP compliance search.google.com/test/amp. AMP or Accelerated Mobile Pages is a Google project you can learn more about here click here www.ampproject.org.
Think with Goole "Test your mobile speed" – This tool tests your website over a 3G mobile connection. Needless to say it is very unforgiving https://testmysite.thinkwithgoogle.com/.
Pingdom Website Speed Test – A great tool for testing website speed and performance from multiple locations https://tools.pingdom.com.
GT Metrixs – Another great overall page performance testing tool https://gtmetrix.com.
Web Page Test – This tool gives you an A, B, C, D or F score for optimization perimeters https://www.webpagetest.org/.
Varvy tools – Vary has tools for analyzing your websites SEO, Speed, and Mobile compliance https://varvy.com/.