Google PageSpeed Insights is probably the most accessible and most comprehensive tool to use when comes the time to measure your website speed. It’ll test the speed of any given URL for desktop and mobile, and for both, you’ll get a page speed score and optimization suggestions. Let’s see more in details what you’ll get while using Google PageSpeed Insights.
Page load Distributions
The Page Load Distributions includes stats for the First Contentful Paint (FCP) and the Dom Content Loaded (DCL). The FCP measures when the user sees a visual response from the page currently analyzed, and the DCL measures how long it takes for an HTML document to be loaded and parsed.
If you’re not familiar with FCP and DCL, Google has a very detailed post regarding these user-centric performance metrics. In that post, Google also talks about Time to Interactive (TTI) and how to calculate it. If you also want more details regarding the PageSpeed Insights Rules used for calculating the score, Google gives more information on its website.
Page Stats
Google gives you two different scores for both mobile and desktop:
- Page Speed, which also includes the stats regarding the FCP and DCL.
- Optimization, which is a percentage based on the number of optimizations already present on the page.
Optimization Suggestions
Google PageSpeed Insights gives you suggestions for optimizing the page being analyzed, such as leveraging browser caching, eliminating render-blocking JavaScript & CSS in above-the-fold content, or identifying which images should be compressed and which JS and CSS files you could minify. You’ll know which files need to be optimized precisely.
Even better, Google takes care of optimizing all the files for you. It might be easy to miss but search for “Download optimized image, JavaScript, and CSS resources for this page” which you can find at the bottom of a Google PageSpeed Insights results page like you can see in the screenshot below:
Finally, you can also try the Test My Site tool on Think With Google website, which will help you test your website on mobile more thoroughly. It also gives you useful stats such as an estimate of visitor loss due to slow loading time.
In the next post of this series, we’ll review the Pingdom Website Speed Test service.
