'Page Speed Is a Lie': Why 'Core Web Vitals' (LCP, INP, CLS) Are What Really Matter

For over a decade, SEOs have obsessed over the 0-100 "page speed score," spending weeks trying to move a score from 88 to 95. But this abstract "performance score" is a distraction. A user doesn't feel a "score" of 95; they feel a page that loads instantly, a button that reacts, and the frustration of a layout that jumps.

Google’s ranking algorithms now reflect this reality, shifting from ambiguous "speed" signals to a concrete, human-centric framework called Core Web Vitals (CWV). If you’re still chasing a 100/100 score while ignoring LCP, INP, and CLS, you are optimizing for the wrong thing.

From "Page Speed" to "Page Experience"

This shift is part of Google’s "Page Experience" update. Google no longer just asks, "Is this page fast in a lab?" It asks, "Is this page delightful for a real human to use?"

This new standard applies to every site, from a small blog to a massive, dynamic platform. For instance, a complex, high-traffic site like an online Casino Spin must obsess over these vitals. A responsive, stable, and fast-loading game lobby is crucial for their user experience, as a laggy interface or a layout shift could cost them a player. Google now holds all web properties to this same standard of user-centric design.

This means we must deconstruct the three specific metrics Google uses as a direct ranking signal.

Deconstructing the Vitals: LCP, INP, and CLS

Core Web Vitals are measurable metrics that quantify a user's experience with loading, interactivity, and visual stability by answering three simple questions.

This table breaks down the "vitals" you need to know:

These are direct measurements of user frustration. A slow LCP means a blank screen. A high INP means a dead button. A high CLS means the user clicks an ad by mistake because the layout jumped.

Fixing the Real Problem: A Triage Guide

A 100/100 performance score means nothing if your real-world CLS is failing. The first step is to find and fix your weakest link.

Tackling Poor LCP (Loading)

A slow LCP is a "first-load" problem, where the browser struggles to get the main "hero" image or text block onto the screen.

Common culprits include:

●     Unoptimized images: Huge .png or .jpg files used where a compressed .webp should be.

●     Slow server response times: The server itself is taking too long to send data.

●     Render-blocking resources: CSS or JavaScript files that must load before content can be shown.

The Fix: Start by compressing your LCP element (usually an image) and ensuring it's preloaded so the browser prioritizes it.

Taming Bad INP (Interactivity)

Interaction to Next Paint (INP) replaced First Input Delay (FID) as a Core Web Vital in March 2024. It's more accurate as it measures all interactions, not just the first. A high INP is almost always caused by heavy JavaScript "blocking the main thread," leaving the browser too busy to respond to a user's click.

The Fix: Identify and break up long-running JavaScript tasks, and defer any scripts not essential for the initial page load.

Stabilizing High CLS (Visual Stability)

High CLS is intensely frustrating and happens when elements load late, pushing other content out of the way.

Common culprits include:

●     Images or videos without dimensions: The browser doesn't know how much space to save, so the page jumps when the media loads.

●     Ads and iframes: Third-party elements load late and shove content aside.

●     Web fonts loading: A "flash" of a different-sized font causes a reflow.

The Fix: This is often the easiest fix. Always specify width and height attributes on your <img> and <video> tags. For ads, reserve a container <div> with a fixed min-height.

Stop Chasing the Score, Start Chasing the Experience

The next time you open a performance report, ignore the big 0-100 score—it’s a vanity metric. Instead, scroll down to the Core Web Vitals report and look at your "Field Data." This data comes from real Chrome users on your site, and it’s what Google uses for ranking.

Your call to action is to stop chasing the "score" and start fixing the experience. Find your single worst Core Web Vital—the one with the most "Poor" or "Needs Improvement" URLs—and focus all your efforts on fixing that one, real-world problem. That is what will improve your user's experience and your rankings.