The tool is built on what's known as Core Web Vitals, three metrics Google uses to evaluate user experience:
While the older FID metric only measured the first interaction, INP replaced it in 2024 and tracks responsiveness for as long as the user stays on the page. Google pulls this data from real Chrome traffic rather than lab tests, so the result reflects what your visitors actually experience.
Core Web Vitals are part of how Google determines search rankings. They're not the main factor, but among competing results of similar content quality, they can be the deciding one. And more importantly, a slow site loses people before they ever get to send an inquiry. For B2B companies, where the cost per click is high, that matters twice as much.
It's also worth knowing that Google evaluates the mobile version of your site first and foremost. Even if your B2B audience mostly browses from a laptop, Google builds its numbers from real user behavior across devices, and a mobile network or a weaker phone will always put page speed to the toughest test. A site that feels snappy on desktop can behave completely differently on mobile. That's why it pays to check both versions separately rather than assuming a good desktop result means a good result everywhere.
Open PageSpeed Insights, enter your website's address, and wait for the result. You'll get three scores, each marked green, orange, or red. Here's how to handle them.
There's no point fine-tuning a metric that's already fine. Pick the worst one and tackle it first.
Large photos are the most common reason a page loads slowly. Resize them and save them as WebP instead of a standard JPG or PNG. You'll cut file size by tens of percent without any visible loss in quality. If you have video on your site, don't let it autoplay as soon as the page loads. Set a thumbnail image instead and only start playback when the user clicks, which saves the tens of percent of data that would otherwise download for nothing.
This means the page is slow to respond to clicks. It's usually caused by scripts that run immediately on load even though the user doesn't need them yet. They can be deferred until later.
Typically ads, banners, or images without a fixed size. Reserving space for them in advance stops them from shifting the content under the reader's cursor.
Results in the tool don't update instantly. Google calculates them from the last 28 days of traffic, so you'll see the improvement only after a few weeks.
PageSpeed Insights isn't a one-off test you check off and forget. It's a metric worth revisiting with every major update to your site. A fast website doesn't just mean a better search ranking. It mainly means more people who stay on the page long enough to remember you, or even reach out.
