Understanding your PageSpeed Insights report

If you have a website, you may have heard that optimizing the performance of your website is important both for a positive user experience and for search engine optimization. There’s several tools that will give you information about the optimization of your site, including Google’s PageSpeed Insights. But, what they don’t tell you is what to do with the information once you have the report. (It’s like those things you can buy to find out the error codes your car is giving – if you don’t know how to interpret the information, it’s more frustrating than helpful.) Have no fear – I’m going to tell you how to understand the your PageSpeed Insights report tells you. 

The PageSpeed Insights report is broken into two tabs – Mobile and Desktop – and then each of those is broken down into several sections. Since January 2018, Google has been emphasizing mobile site performance as a ranking factor, so it’s important to look at those results as well as your basic Desktop results. The mobile testing is done over a 4G connection, so your own device may have different results when testing.

Breaking down the information

Each tab in your report has the following information: Overall Score, Field Data, Origin Summary, Lab Data, Opportunities, Diagnostics, and Passed Audits. Let’s look at each of these sections. 

Overall Score

First things first – this score can be very misleading. It’s basically just a metric of the audit criteria that it’s passed, but it should not be taken the final word on the optimization of your site. I’ve seen sites that take forever to load or with very large page sizes score high, and fast loading sites score low. Many people can become more worried about their site when they see this score, but it should be taken with a grain of salt, so to speak. Rather, the rest of the information on the page is the more important part to act on.

Field Data & Origin Summary

The Field Data & Origin Summary sections shows information gathered by Google from “real-world users.” However, the gathering of data can only be accomplished under a pretty specific set of circumstances (users who have opted-in to syncing their browsing history, have not set up a Sync passphrase, and have usage statistic reporting enabled) and doesn’t seem to apply to a large group of people. Do not be alarmed if there’s no information in this area. 

Lab Data

The Lab Data section of your PageSpeed Insights reports give you some very important metrics – First Contentful Paint, First Meaningful Paint, Speed Index, First CPU Idle, Time to Interactive, and Estimated Input Latency.

  • First Contentul Paint is the time it takes to show content after the page has been navigated to. While the overall page load time is different, this usually refers to the time it takes for visitors to see some part of your website in their browser. 
  • First Meaningful Paint is the “time at which the user feels that the primary content of the page is visible.” Ideally, this should be the same as the First Contentful Paint.
  • Speed Index “shows you how quickly the contents of a page are visibly populated.” Obviously here, the lower the time, the better. 
  • First CPU Idle refers to the amount of time needed for most of the elements on the page to be active, and for the page to be minimally interactive for your visitors. 
  • Time to Interactive is a metric that measures how long it takes a page to become interactive. “Interactive” is defined as the point where the page has displayed useful content, event handlers are registered for most visible page elements, and the page responds to user interactions within 50 milliseconds.
  • Estimated Input Latency refers to how quickly your site refers to user interaction, timed in milliseconds.

(refer to https://developers.google.com/speed/docs/insights/v5/about for more information)

Each metric is also scored and that score is use displayed through the use of colored text and an icon. 

  • Fast is indicated with a green text and a check mark
  • Average speed is indicated with orange text and an informational circle
  • A slow speed is indicated with red text and a warning triangle

Opportunities

The Opportunities section shows you areas that could be optimized to increase your performance. Some examples of these opportunities could be image optimization, deferring render-blocking JavaScript, CSS or images, or avoiding page redirects. While there are common issues, your PageSpeed Insights report is going to be generated relative to your site, so this is a good area to pay attention to.

Diagnostics

This section provides additional information about your page/site in relation to some web development best practices.

Passed Audits

The Passed Audits section lists the evaluation criteria that your website has passed. This is good, and you don’t need to worry a lot about this section unless it changes and you have a lower number of Passed Audits in subsequent reports. 

What to do after you review the report

After you review your PageSpeed Insights report, you’ll want to look for ways to optimize the performance of your site. Again, a well-optimized site is better for user experience and search engine ranking. The first and most impactful step is usually to make sure you are using a good host. All the optimization techniques in the world aren’t going to help if your host is slow. 

If you need help applying optimization techniques to your website, check out my website optimization audit service to get your site moving faster than ever.

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