Rebel Insights

Google’s June 2021 Lighthouse Update Changes PageSpeed Insights Performance

pagespeed insights june 2021

Google updated how their PageSpeed Insights scores are calculated by releasing a new version of Lighthouse on June 1, 2021. Lighthouse is a tool built into Google Chrome that lets you know how well your site is performing against Google's standards for a better open web. At RebelMouse, our team keeps up with updates from Google closely, and reads all of their release notes and GitHub updates.

This latest upgrade to Lighthouse had a negative impact on one of our previous methods for loading JavaScript in the JavaScript element of our Layout & Design Tool . Performance scores dropped as much as 20–60 points for sites that were using the JavaScript element in its previous state. However, our team kept on top of Google's changes, and developed a new approach that we call the post Largest Contentful Paint (LCP) method. LCP is a metric in Google's Core Web Vitals that measures the time it takes to load the main content on a page. Our post-LCP method loads JavaScript immediately after the LCP event has completed. Thanks to this new approach, scores in our site network have largely stayed intact, and many of them significantly outperform the open web.


Additionally, on June 17, 2021, we released a platform update to improve our Load Blocking element, which fires JavaScript immediately after the page has completed loading. Previously, this method received negative performance scores after Google's June 1 changes. But now that we've made our update, no changes are necessary to sites that are using this element.

It's important to note that Chrome User Experience Report (CRUX) scores and Lighthouse scores are not entirely aligned and often disagree with each other. Please follow best practices on our platform, as described here , to stay ahead of Google's algorithm changes.

If you have any questions about the latest version of Lighthouse, or any of these updates, please email support@rebelmouse.com or talk to your account manager today.

Related Articles

What Is RebelMouse?
Request a Proposal

Where
Websites Are Built

The Fastest Sites in the World Run on RebelMouse

Let’s Chat

new!

RebelMouse Performance Monitoring

Real-Time Core Web Vitals

Get Started
DISCOVER MORE

Our Core Features

Our platform is a complete digital publishing toolbox that's built for modern-day content creators, and includes game-changing features such as our:

Why RebelMouse?

Unprecedented Scale

RebelMouse sites reach more than 120M people a month, with an always-modern solution that combines cutting-edge technology with decades of media savvy. And due to our massive scale, 1 in 3 Americans have visited a website powered by RebelMouse.

120M+ Users
550M+ Pageviews
17+ Avg. Minutes per User
6+ Avg. Pages per User

Today's Top Websites Use RebelMouse

Thanks to the tremendous scale of our network, we are able to analyze a wealth of traffic data that informs our strategies and allows us to be a true strategic partner instead of just a vendor.

What Clients Say

We’re here to help you weigh and understand every tech and strategic decision that affects your digital presence. Spend less time managing everything yourself, and more time focused on creating the quality content your users deserve.

Case Studies

A Team Built Like No Other

RebelMouse employs a unique, diverse, and decentralized team that consists of 70+ digital traffic experts across more than 25 different countries. We have no central office, and we cover every time zone to ensure that we’re able to deliver amazing results and enterprise-grade support around the clock.

Our team is well-versed in all things product, content, traffic, and revenue, and we strategically deploy ourselves to help with each element across all of our clients. We thrive on solving the complex.

Let's Chat