Lighthouse, the technology that powers audits in Chrome Dev Tools and PageSpeed Insights updated to version 8.3.0. The new version features bug fixes and incremental improvements but it also takes the first step toward measuring what happens after a web page loads. This new direction is called Project Fraggle Rock.
The updated version of Lighthouse is live on PageSpeed Insights. It is scheduled to be released in Chrome Dev Tools in Chrome 94 on September 21, 2021.
Google Lighthouse is an open source tool created by Google that tests web pages for web performance bottlenecks, accessibility issues and identify SEO opportunities.
Because the tool is open source, the underlying code that powers Lighthouse can be found in numerous third party tools, some of which extend Lighthouse by adding different capabilities and more helpful data visualizations.
That means that any changes to Lighthouse will inevitably make it into third party tools as well.
Lighthouse can be used as part of the Chrome Dev Tools suite of tools that is native in every Chrome-based browser.
Lighthouse 8.3.0 is coming Chrome 94, which is due to be released on September 21, 2021.
PageSpeed Insights Updates to Lighthouse 8.3.0
PageSpeed Insights is a web page performance measurement tool that is also produced by Google. Google Lighthouse powers PageSpeed Insights.
The difference between PageSpeed Insights and the Lighthouse tool is that PageSpeed insights only shows the web page performance metrics and is strictly focused on that metric.
PageSpeed Insights does not show the rest of the data that Lighthouse presents which includes accessibility and SEO.
What’s New in Lighthouse 8.3.0
There are no big shifts in how Core Web Vitals are measured. But version 8.3.0 represents a little step toward bigger things in the future and also includes bug fixes.
Lighthouse Fraggle Rock Project
Lighthouse 8.3.0 takes a small step toward moving beyond analyzing a single web page and expanding to also analyzing user flows.
The future of Lighthouse is analyzing flows from when a user takes an action like clicking a button and what happens next.
Lighthouse currently measures things like how long it takes for a web page to become interactive.
The new running on flows direction will measure what happens after the page loads.
This project is whimsically called Fraggle Rock, which is the name of a 1980’s Children’s show that featured a lighthouse referred to as the Fraggle Rock Lighthouse.
The current description of the Fraggle Rock project is officially summarized:
“Fraggle Rock (Lighthouse scripted scenarios) allows a developer to get a Lighthouse report beyond an initial page load. This is valuable as it provides developers with insight into performance & best practices for complex user flows like sign-up, add-to-cart, time-to-tweet, etc.”
The official GitHub page for the new feature describes four scenarios:
- “Run snapshot-style audits on a page after interaction, i.e. I’ve clicked a menu option and now rerun the accessibility category
- Run timespan-style audits on a page during any arbitrary interaction
- Run Lighthouse on a traditional page navigation from an existing page
- Run Lighthouse on a single page app navigation”
There are eight (tentative) phases for bringing running flows to Lighthouse.
The Lighthouse team is currently in Phase zero, which is the planning phase.
“Phase 0 – Research & Design
- Create an inventory of all audits cataloging their implicit requirements (e.g. snapshot v. timespan v. load) Complete
- Create design doc and project plan Complete”
Phases 1 – 8 are not complete so it’s clear that the Lighthouse team is at the beginning of an important update that will dramatically change this tool.
Lighthouse 8.3.0 Bug Fixes
Lighthouse 8.3.0 also features bug fixes and small improvements, some of which were suggestions from the developer community that were frustrated with issues they discovered.
For example, one of the fixes was to address the “resource size calculation of cached images.”
One of the developers commented:
“The original reason we wanted to disable cache was because when calculating resource size, the gatherer takes transferSize into account, which is 0 for cached images. Images coming from cache are therefore ignored by this gatherer. This seems to be unwanted behavior as it shouldn’t matter whether an image is cached or not to optimize it.
Turning off cache fixed the issue but added on average 10 seconds to our lighthouse runs. I’m wondering if the aforementioned code isn’t actually unintentionally discarding cached images.”
Lighthouse SEO Category Reworded
The SEO category of Lighthouse was reworded in order to emphasize Core Web Vitals (CWV).
The new wording also removes the explicit reference to improving search results ranking and replaces that reference with the words “search engine optimization advice” which is more neutral in terms of promises of rocking the top of the search engine results pages.
The official GitHub page for this change states:
“Updates our SEO category description to tone down its comprehensiveness and remind the user about CWV.”
Previous Lighthouse SEO description:
“These checks ensure that your page is optimized for search engine results ranking.
There are additional factors Lighthouse does not check that may affect your search ranking.”
The new Lighthouse SEO description now reads like this:
“These checks ensure that your page is following basic search engine optimization advice.
There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more.”
Lighthouse 8.3.0 Summary of Changes
It’s realistic that the Lighthouse team reworded the SEO section to more accurately define SEO as optimization for search engines and pull back any association with ranking better.
Clearly the most interesting part of Lighthouse 8.3.0 announcement is the Fraggle Rock project, which will be covered in more detail soon.
Lighthouse 8.3.0 Release Notes