Lighthouse PageSpeed Insights Update

Following the release of Version 5 of Google’s PageSpeed Insights tool, many site owners have been left wondering what on earth this ‘Lighthouse’ tool is. Lighthouse is a site-audit tool created by Google, which site owners can use to assess the quality of their webpages and find the areas for improvement. It started out as a Google Chrome Extension that users could download to compile a report of a particular website. The report mainly focuses on data surrounding the site’s speed, and also makes further suggestions as to how the site can align with best practices.

What has it got to do with PageSpeed Insights?

While Lighthouse has been available as an extension for a few years now, it was only in November 2018 that Google decided to incorporate Lighthouse into its PageSpeed Insights tool. This is the first major update Google have made to the tool since they announced that the tool would now use real user data from Google Chrome in January 2018.  As a result of the Version 5 update, PageSpeed Insights now uses Lighthouse in conjunction with data provided by the Chrome User Experience Report (CrUX).

How has this affected PageSpeed Insights?

Along with this new version of PageSpeed Insights has come a swanky new look for the  dashboard:


Google PageSpeed Insights interface new


The data on the report maintains some of the metrics featured on the original version of PageSpeed Insights, but also comes with some new additions:

  • Field Data: Version 5 of PageSpeed Insights has kept the First Contentful Paint (FCP) metric, but has replaced what used to be DOM Content Loaded (DCL) with First Input Delay (FID). FCP measures the time it takes for the first bit of content to render following navigation to a website. FID measures the time from when a user interacts with a site to the time when the site responds to the interaction. Google uses CrUX to gather this data.
  • Lab Data: This is a new addition to the PageSpeed report, and is made up of data that is gathered by Lighthouse. It emulates the page in question on a mobile network to plot metrics such as FCP, Speed Index (how quickly the contents of a page are visibly populated), Time to Interactive (the time at which the page is fully interactive), First CPU Idle (the first point at which a page’s main thread is quiet enough to handle input) and Estimated Input Latency (an estimate of how long the page takes to respond to the user in the busiest 5 second window of page load time).
  • Opportunities: This section suggests the changes you can make to your site to further optimise page load time.
  • Diagnostics: This gives you a run down on how your site is performing in areas such as DOM size, JavaScript, cache etc.

Why should I care?

Site owners should care about this update because it has made it as easy as ever to monitor and improve your website’s performance. As you might know by now, Internet users are very impatient. Because of this, page speed is an incredibly important aspect of SEO. In fact, Google found that 53% of users will leave a page if it takes more than three seconds to load.

Considering that Google released the Mobile Speed Update earlier this year, if you haven’t looked at addressing load speed issues already, we would highly recommend placing this high on your list of priorities. A fast loading webpage may not get you ranking at the top of the results, but a slow loading website will almost certainly prevent you from reaching the top. In fact, with this new data being included in Google’s scoring of websites on PageSpeed Insights, there have been reports of websites scoring very low when previously they have scored well. There are more factors to take into account than just straight load speed so get your techies on the case!

Therefore, be thankful that Google has made PageSpeed Insights as insightful as ever (ha) through the introduction of Lighthouse to the performance tool. Site owners should also bear in mind that they will soon have to upgrade their API to the new version of PageSpeed insights, as the API of Version 4 will be deprecated in May 2019. Of course, there are also other speed tools that will give you more granular detail such as GT Metrix or WebpageTest.

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