Lighthouse is an open-source, automated tool for improving the quality of web pages. ⠀
You can run it against any web page, public or requiring authentication. ⠀
It has audits for performance, accessibility, progressive web apps, and more.

Image from video and above description from Lighthouse website.
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To run it in Google Chrome follow the below steps.⠀

1. Open Devtools⠀
2. Click Audit tab⠀
3. Click Run audits

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It has some great tips and resources for how to improve your site.⠀
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However one thing to keep in mind is that getting a good score on the audit doesn't mean you have the perfect site, for example it doesn't rate the quality of your design, content, usability etc, you should find the right balance between meeting your clients needs and making sure it is as fast as possible.

Once again if you are interested in finding out more about this awesome tool I highly recommend heading over to the lighthouse website.

And I will aim to do a deeper dive into the functionality at a later date.