Your page loads fine on your own laptop, yet Google Search Console still flags it as failing, and that is where most business owners hit a wall. The page feels fast to you, so the red score makes no sense.
According to the 2025 Web Almanac by HTTP Archive, which analyses performance across millions of real pages, only 48% of mobile pages pass all three Core Web Vitals. More than half the web is failing the exact metrics Google uses to judge page experience.
So the real question becomes: if most sites cannot pass, what are the few that are actually doing differently?
What Are Core Web Vitals
Core Web Vitals are three metrics Google uses to measure the real-world experience of loading and using your page. They are built from field data collected from actual Chrome users, not from a lab test on a fast connection, which is why a page can feel quick to you and still fail.
Google scores each metric as Good, Needs Improvement, or Poor. The bar is collective: at least 75% of your real page visits must hit the Good threshold for a URL to pass. The assessment runs on your typical visitor, not your best-case load.
Key Core Web Vitals elements:
- Largest Contentful Paint (LCP): Measures loading speed, how long the largest visible element (usually a hero image or headline) takes to render. Good is under 2.5 seconds.
- Interaction to Next Paint (INP): Measures responsiveness, how long the page takes to react after a tap, click, or keypress. Good is under 200 milliseconds.
- Cumulative Layout Shift (CLS): Measures visual stability, how much content jumps around as the page settles. Good is under 0.1.
- Field data over lab data: The score that counts comes from real users via the Chrome User Experience Report, not from a one-off Lighthouse run.
- The 75th percentile rule: Passing means 75% of visits clear the threshold, so you optimise for your slowest realistic visitor, not your fastest.
For example, if you run a service business, your homepage might carry a heavy hero image (an LCP problem), a chat widget that delays the first tap (an INP problem), and an ad or cookie banner that shoves the layout down as it loads (a CLS problem). Each maps to a different vital, which is why a single “make it faster” fix rarely moves all three.
How to Improve Your Core Web Vitals: Step-by-Step Guide
Here are the steps to improve your Core Web Vitals and strengthen your Google page experience score.
1. Diagnose With Field Data, Not Lab Scores
Start by measuring the dataset Google actually grades you on. A perfect Lighthouse result while Search Console shows red is the single most common reason teams optimise confidently in the wrong direction, because Lighthouse is a lab test and your ranking depends on field data.
Open Google Search Console’s Core Web Vitals report to see which URLs fail and on which metric, then run individual pages through Google PageSpeed Insights to view both field and lab data side by side. The field section, drawn from the Chrome User Experience Report, is the one that matches your assessment and provides reliable web performance metrics.
For example, before changing a single image or script, note your current LCP CLS FID values per template. Those numbers become the baseline you measure every later fix against, so you can prove what worked instead of guessing.
2. Fix Cumulative Layout Shift First
CLS is often the quickest Core Web Vitals issue to fix because it rarely affects application logic. Adding dimensions to images and videos, reserving space for ads and embeds, and preventing font-related layout shifts can significantly reduce unexpected content movement.
Elements such as cookie banners and promotional bars should load within pre-allocated space to maintain a stable page layout and provide a better user experience. Improving CLS also supports website speed SEO efforts because stable pages tend to load more efficiently.
Here is what those fixes look like in practice on a typical page:
| Common cause of shift | Before (causes CLS) | After (the fix) |
| Hero image | <img src=”hero.jpg”> with no dimensions | <img src=”hero.jpg” width=”1200″ height=”600″> |
| Display ad | Ad injected with no reserved slot | Container with fixed min-height set before load |
| Cookie banner | Drops in at the top, pushes content down | Overlaid with position: fixed, no layout impact |
| Web font | Swaps in at a different size, text reflows | font-display: swap with a size-matched fallback |
3. Attack Largest Contentful Paint
LCP is the metric that fails the most sites, so it deserves the most attention once CLS is handled. According to the 2025 Web Almanac, only 62% of mobile pages clear the LCP threshold, making loading speed the primary bottleneck for overall Core Web Vitals.
Focus on the largest above-the-fold element. Compress and serve your hero image in a next-gen format like WebP or AVIF, preload it so the browser fetches it early, reduce server response time, and lazy-load anything below the fold so it does not compete for bandwidth. A content delivery network shortens the distance between your server and the visitor, which often produces the single biggest LCP gain.
For example, swapping an uncompressed 1.5 MB hero PNG for a properly sized WebP and preloading it can cut LCP by a full second or more on mobile, which is frequently the difference between a Poor and a Good rating. These improvements help improve Core Web Vitals and create a stronger Google page experience signal.
4. Reduce Interaction to Next Paint
INP is the hardest vital to pass, and the one most older guides get wrong. In March 2024, Google retired First Input Delay (FID) and replaced it with INP, so any advice still teaching FID is out of date. LCP CLS FID remains a familiar term for many SEO professionals, even though INP has replaced FID as the responsiveness metric.
INP failures almost always trace back to JavaScript holding the main thread hostage. Audit your third-party scripts (analytics, chat widgets, ad tags), defer or remove the non-essential ones, break up long JavaScript tasks, and minimise the code your page builder ships. Use Chrome DevTools’ Performance panel to see exactly which scripts run long tasks.
One honest caveat: when the root cause is a heavy page builder generating bloated JavaScript, there is a ceiling on how far you can improve INP without addressing the underlying build. Knowing that early saves you from chasing fixes that cannot work.
5. Optimize Images and Media Properly
Images are often the largest assets on a page, so optimising them can improve LCP, CLS, and overall page speed at the same time. According to the HTTP Archive Web Almanac, the median mobile webpage weighs approximately 1.8 MB, with images accounting for a significant portion of that total, making image optimisation one of the most effective technical SEO improvements.
Compress images, use modern formats such as WebP or AVIF, size images according to their display dimensions, and always include width and height attributes to prevent layout shifts. Adding descriptive alt text also improves accessibility and image search visibility.
Image optimisation remains one of the most effective website speed SEO techniques because it improves loading times while also enhancing the user experience.
6. Monitor Continuously, Not Once
Core Web Vitals are not a one-time task. New plugins, scripts, design changes, and marketing tags can gradually reduce your site’s performance, which makes regular monitoring an essential part of technical SEO.
For example, many websites experience a decline in their Core Web Vitals scores after adding third-party tools such as chat widgets, tracking scripts, or advertising tags. Google Search Console often reports pages moving from “Good” to “Needs Improvement” after these changes increase loading times or cause layout shifts.
Review your Core Web Vitals reports regularly and test your site after every major update. Since Google increasingly evaluates page experience across groups of pages, maintaining strong performance throughout the entire website is now more important than optimising only a few key landing pages.
Supercharge Your Page Experience With Expert Technical SEO
Even a clear step-by-step plan can stall when LCP traces back to hosting, or INP traces back to a page builder you cannot easily change. Core Web Vitals sit inside the wider technical SEO foundation, alongside crawlability, mobile performance, and site architecture, and they compound with every other ranking signal on the page.
This is exactly the work Sam SEO Philippines improves Core Web Vitals through proven technical SEO strategies backed by 8 years of experience. Every issue is diagnosed and resolved with a clear, prioritised action plan. The focus is on long-term performance improvements that keep your scores in the green. Book a free SEO strategy call today and gain a competitive advantage.
Frequently Asked Questions on Core Web Vitals
What are Core Web Vitals and why do they matter?
Core Web Vitals are three Google metrics, LCP, INP, and CLS, that measure your page’s loading speed, responsiveness, and visual stability using real Chrome user data. They matter because Google uses them as part of its page experience ranking signals, and passing them improves both your search visibility and the actual experience visitors have on your site.
What is a good Core Web Vitals score?
A passing score means hitting the Good threshold on all three metrics at the 75th percentile of real users: LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. Because the bar is collective, 75% of your page visits must clear every threshold, so you optimize for your typical visitor on a real device, not your fastest test load.
Why did Google replace FID with INP?
Google retired First Input Delay in March 2024 because it only measured the delay before the browser began responding to a visitor’s first interaction, ignoring how long the response took and every interaction afterward. Interaction to Next Paint measures full response latency across the whole visit, making it a far more honest and demanding read on responsiveness. Any guide still teaching FID is out of date.
How do I check my Core Web Vitals?
Use Google Search Console’s Core Web Vitals report to see which URLs fail and on which metric, then run individual pages through Google PageSpeed Insights for field and lab data side by side. The field data, drawn from the Chrome User Experience Report, is what determines your assessment, so prioritise it over lab scores.
Do Core Web Vitals affect SEO rankings?
Yes, Core Web Vitals have been a confirmed ranking factor within Google’s page experience signals since 2021, but they work as a tiebreaker rather than a dominant force. When two pages have comparable content and authority, the one that passes gains a measurable edge, especially in competitive niches. They will not rescue weak content, so treat them as the deciding margin where you already compete on substance.
Can I improve Core Web Vitals without rebuilding my site?
For LCP and CLS, often yes: compressing images, serving next-gen formats, assigning fixed dimensions to media, and optimising fonts are changes you can make without a rebuild. INP is harder, because when failures come from a page builder generating excessive JavaScript, there is a ceiling on improvement until the underlying build is addressed. Auditing INP early helps you avoid expensive surprises later.
How long does it take to improve Core Web Vitals?
Technical fixes like image compression and reserving layout space can show up in lab tests immediately, but the field data Google grades you on updates on a rolling 28-day window. That means your Search Console assessment typically reflects improvements a few weeks after you deploy them, so consistent monitoring matters more than waiting for an instant result.