Your PageSpeed score just went up. Your website might not be any faster

If your PageSpeed Insights score has jumped in the last few days, your website probably has not suddenly become faster. Google's free speed test now runs Lighthouse 13.6.0, released on 27 October 2026, which changes how it estimates page loading. As Search Engine Journal reported on 2 November, Chrome's Web Performance Developer Advocate Barry Pollard says the new version is more accurate and generally produces higher scores.

That sounds like good news. But if you are comparing this month's report with last month's, or paying someone to improve your site speed, a higher number may come from the test changing rather than your website.

What changed in PageSpeed Insights

PageSpeed Insights is Google's free tool for checking how quickly a web page loads on mobile and desktop. The big score at the top, from 0 to 100, comes from Lighthouse, a testing engine built by the Google Chrome team.

Lighthouse does not test your page on a real phone. It loads the page quickly in a Google data centre, then uses a simulation called Lantern to estimate how that page would load on a mid-range phone over a mobile connection. Version 13.6.0 changes that simulation in a few ways:

• Better guesses about what blocks the page. Lantern now uses Chrome's own label for files that hold up the page from appearing, rather than guessing from each file's priority.
• Fairer handling of text-led pages. When the main thing on screen is text that appears at the same moment as the first content, the test now estimates both from the same set of files. Previously it could make the main content look much slower than it really was.
• Updated network modelling. Modern connections such as HTTP/3 are now treated as able to download several files at once, which is closer to how they really behave.

According to the Lighthouse release notes, the team expected the update to reach PageSpeed Insights within a week of release. Pollard added that websites relying heavily on JavaScript are the most likely to see a difference.

Why your score can change when your website has not

The quick facts:

• Lighthouse 13.6.0 was released on 27 October 2026.
• PageSpeed Insights had switched to it by 2 November 2026.
• Lab scores before and after that date were produced by different versions of the simulation, so they are not a like-for-like comparison.
• JavaScript-heavy sites, such as those built with page builders or app-style frameworks, are the most likely to move.
• Chrome 159, due on 8 December according to Chrome's release schedule, is expected to bring the same version into Chrome's built-in developer tools. It is another sign that Chrome updates arrive faster than they used to.

Google's own PageSpeed Insights documentation already warns that scores vary from run to run, even when nothing on the page changes. This update adds a bigger, one-off shift on top of that normal wobble.

If this sounds familiar, it is. Last month we explained why rank trackers were showing false drops in Google rankings. The lesson is the same here. When a report suddenly moves, check whether the measuring tool changed before you assume your website did.

Lab data and field data are not the same thing

Every PageSpeed Insights report shows two kinds of data, and knowing the difference is the most useful thing you can take from this update.

Lab data is the 0 to 100 score from the Lighthouse simulation. Google treats 90 and above as good, 50 to 89 as needing improvement and below 50 as poor. It is useful for spotting problems, but it is a test on one simulated device, not a measure of real visitors.

Field data is the section headed "Discover what your real users are experiencing". It comes from the Chrome User Experience Report, which collects anonymised speed data from real Chrome users over the previous 28 days. This is where you see your Core Web Vitals:

• Largest Contentful Paint (LCP): how long the main content takes to appear. Good is 2.5 seconds or less.
• Interaction to Next Paint (INP): how quickly the page responds to a tap or click. Good is 200 milliseconds or less.
• Cumulative Layout Shift (CLS): how much the page jumps around while loading. Good is 0.1 or less.

The Lighthouse update changes the lab score only. It does not change your field data, because your real visitors' experience has not changed. Google's guidance on Core Web Vitals and search results describes these as measures of real-world user experience, and recommends site owners aim for good scores for success in Search. In plain English, the real-visitor numbers are the ones that matter most.

Smaller websites sometimes see no field data at all, because there are not yet enough Chrome visitors to report on. In that case, treat the lab score as a rough guide rather than chasing a perfect 100.

What this means for your business

For most small businesses, nothing needs fixing because of this update. But it is worth adjusting how you read your speed reports over the next few months.

1. Check the Lighthouse version. At the bottom of every PageSpeed Insights report, next to the emulated device, you will see which version of Lighthouse was used. Only compare scores that used the same version.
2. Lead with field data. If your report shows Core Web Vitals from real users, judge your site's speed on those first. A lab score going from 72 to 85 means little if your real visitors still wait four seconds for the page to appear.
3. Ask for before and after evidence. If a developer or agency reports a big speed improvement in early November, it is fair to ask how much came from their work and how much from the new test. Good suppliers will be glad to show you the field data.
4. Use Search Console for the bigger picture. The Core Web Vitals report in Google Search Console groups your pages by real-user speed. Our guide to getting started with Google Search Console explains where to find it.
5. Do not undo good work. If a score drops on a page that changed recently, check the version and the field data before rolling anything back.

If your site still feels slow on your own phone, it probably is, whatever the score says. Heavy page builders, oversized images and too many plugins are the usual causes. A well-built site from our website design and development team starts lean, so speed is not something you have to keep chasing.

FAQ

Why did my PageSpeed Insights score change when I did not change anything?

Google's PageSpeed Insights switched to Lighthouse 13.6.0 in early November 2026, which estimates page loading differently and usually gives higher scores. Scores also vary a little between runs because of network and test machine conditions.

Does my PageSpeed Insights score affect my Google ranking?

Google's ranking systems look at page experience, and its guidance on Core Web Vitals focuses on real-world user data. The 0 to 100 lab score is a diagnostic tool, so treat your field data and the Search Console Core Web Vitals report as the more important signals.

What is the difference between lab data and field data?

Lab data is a simulated test on one device and connection, run when you click analyse. Field data comes from real Chrome users visiting your site over the previous 28 days. When the two disagree, field data reflects what your customers actually experience.

What is a good PageSpeed Insights score?

Google treats a lab score of 90 or above as good. For real visitors, aim for an LCP of 2.5 seconds or less, an INP of 200 milliseconds or less and a CLS of 0.1 or less.

What to do next

Enjoy the higher score if you have one, but do not take it as proof your website is faster. Check the Lighthouse version, look at your real-user data and keep an eye on how the site feels on a phone.

If you would like someone to look at the numbers with you, our SEO and GEO services include speed and Core Web Vitals checks, and our costs page sets out what that looks like. If your current site is slow however you measure it, the simplest first step is our free website offer.