In this article, we uncover how PageSpeed calculates it’s critical speed score.
It’s no secret that speed has become a crucial factor in increasing revenue and lowering abandonment rates. Now that Google uses page speed as a ranking factor, many organisations have become laser-focused on performance.
Last year Google made two significant changes to their search indexing and ranking algorithms:
- In March, indexing became based on the mobile version of a page, rather than desktop.
- In July, the SEO ranking algorithm was updated to include page speed as a ranking factor for both mobile pages and ads.
From this, we’re able to state two truths:
- The speed of your site on mobile will affect your overall SEO ranking.
- If your pages load slowly, it will reduce your ad quality score, and ads will cost more.
Google wrote:
Faster sites don’t just improve user experience; recent data shows that improving site speed also reduces operating costs. Like us, our users place a lot of value in speed — that’s why we’ve decided to take site speed into account in our search rankings.
To understand how these changes affect us from a performance perspective, we need to grasp the underlying technology. PageSpeed 5.0 is a complete overhaul of previous editions. It’s now being powered by Lighthouse and CrUX (Chrome User Experience Report).
This upgrade also brings a new scoring algorithm that makes it far more challenging to receive a high PageSpeed score.
What changed in PageSpeed 5.0?
Before 5.0, PageSpeed ran a series of heuristics against a given page. If the page has large, uncompressed images, PageSpeed would suggest image compression. No Cache-Headers missing? Add them.
These heuristics were coupled with a set of guidelines that would likely result in better performance if followed, but were merely superficial and didn’t actually analyse the load and render experience that real visitors face.
In PageSpeed 5.0, pages are loaded in a real Chrome browser that is controlled by Lighthouse. Lighthouse records metrics from the browser, applies a scoring model to them and presents an overall performance score. Guidelines for improvement are suggested based on how specific metrics score.
Like PageSpeed, Lighthouse also has a performance score. In PageSpeed 5.0, the performance score is taken from Lighthouse directly. PageSpeed’s speed score is now the same as Lighthouse’s Performance score. – Read more
