What: This guide shares five practical ways to improve Core Web Vitals and enhance website performance.
Who: Website owners, marketers, SEO teams, and developers looking to improve rankings and UX.
Why: Google uses Core Web Vitals as a ranking signal. Slow or unstable pages can hurt visibility and conversions.
How: Step-by-step fixes for LCP, CLS, FID, and INP, plus tools to monitor performance.
In This Article
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Improve user experience and boost SEO by fixing the performance metrics Google cares about most.
Search engines have become more focused on how users experience your website, not just what it says. Core Web Vitals are Google’s way of measuring that experience. These metrics track how fast your site loads, how stable it appears while loading, and how quickly users can interact with it.
In 2025, Core Web Vitals are not just technical details. They are part of the page experience signal that can influence where your site ranks in search results. If your site feels slow, shifts around when loading, or delays user input, it may lose both traffic and credibility.
The good news is that improving Core Web Vitals does not require a complete site rebuild. In this blog, we will explain what these metrics mean, why they matter, and show you five simple and effective fixes that can boost your site’s performance and visibility.
Fix Core Web Vitals Issues and Rank Higher
Learn how to optimise site speed, stability, and responsiveness for a better user experience and stronger SEO performance.
What Are Core Web Vitals? A Quick Guide
Core Web Vitals are a set of user-focused metrics that measure the quality of experience on your website. Introduced by Google, these metrics reflect how quickly your page loads, how visually stable it is, and how responsive it feels to user actions. They apply to all websites and directly influence search rankings.
Here are the main metrics you need to know:
Metric
What It Measures
Good Score
Largest Contentful Paint (LCP)
Loading speed of the main content visible to the user
Under 2.5 seconds
Cumulative Layout Shift (CLS)
Visual stability as the page loads (avoiding sudden shifts)
Less than 0.1
First Input Delay (FID)
Time from first user interaction to browser response
Under 100 milliseconds
Interaction to Next Paint (INP)
A new metric replacing FID, offering a more complete view of interactivity
Under 200 milliseconds
In 2024, Google began shifting from FID to INP as the primary measure of input responsiveness.
These metrics are measured using both lab tools (for developers) and real-world user data. Websites that meet the recommended thresholds across all three metrics are considered to have a good page experience.
Why Core Web Vitals Impact Your Google Rankings
Core Web Vitals are part of Google’s page experience update, which evaluates how users interact with your content beyond just keywords and links. Since this update became a ranking factor in 2021, performance metrics like LCP, CLS, and INP have played a supporting role in how pages are ranked, especially when multiple results are otherwise equal in content relevance.
Google’s goal is to prioritise websites that offer not only valuable information but also a smooth and responsive user experience. This means that pages loading slowly, shifting visually during load, or responding poorly to user actions are considered less helpful, even if their content is strong.
Why Each Metric Matters to Google and Users
Largest Contentful Paint (LCP) A slow LCP means users are left staring at a blank or incomplete page. This increases bounce rates and reduces the chance of engagement or conversion.
Cumulative Layout Shift (CLS) Unexpected layout shifts frustrate users, especially on mobile devices. Pages that move buttons or text during load can cause accidental clicks or reduce trust.
Interaction to Next Paint (INP) Replacing FID, INP tracks how responsive your site feels when users interact with it. A lag between a user clicking and seeing something happen signals a poor experience.
Google uses these metrics across groups of similar pages. If multiple product or blog pages perform poorly on CWV, it can affect the entire group’s visibility.
Mobile Experience Is Key
Because Google uses mobile-first indexing, your site’s mobile Core Web Vitals have a direct impact on how it ranks, even in desktop results. A site that performs well on desktop but poorly on mobile may still lose search visibility if mobile scores are not optimised.
Real-World Example
Many e-commerce websites that improved LCP by compressing product images and reducing third-party scripts saw measurable increases in rankings and revenue. In industries where speed and usability directly affect sales, small performance gains lead to significant SEO and business outcomes.
With Core Web Vitals affecting both how users experience your site and how search engines evaluate it, improving these metrics is no longer optional. It is a vital part of SEO in 2025.
5 Simple Fixes to Improve Core Web Vitals
Improving Core Web Vitals does not always require a complete website redesign. In many cases, a few targeted fixes can significantly boost performance and user experience. These five actions are some of the most effective and accessible ways to improve your LCP, CLS, and INP scores.
Fix 1: Optimise and Compress Images
Large, uncompressed images are one of the most common causes of poor LCP scores. To improve loading speed:
Use next-gen image formats like WebP or AVIF
Resize images to the exact dimensions needed on the page
Apply image compression tools such as TinyPNG or Squoosh
Serve responsive images with the <picture> tag or srcset attribute
Impact: Improves Largest Contentful Paint (LCP), especially on image-heavy landing or product pages.
Fix 2: Eliminate Render-Blocking Resources
Render-blocking scripts delay page loading and interactivity. To reduce their impact:
Defer non-essential JavaScript using defer or async attributes
Minify CSS and JavaScript files to reduce size
Inline critical CSS for above-the-fold content
Remove unused third-party scripts where possible
Impact: Improves both LCP and Interaction to Next Paint (INP) by reducing delays in rendering key elements.
Fix 3: Set Explicit Width and Height for Media
Unexpected layout shifts are often caused by images, videos, or iframes loading without predefined dimensions. To prevent this:
Always set width and height attributes in your HTML
Reserve space for ads or dynamic content blocks
Avoid inserting large elements above existing content after page load
Impact: Reduces Cumulative Layout Shift (CLS) and creates a smoother visual experience.
Fix 4: Reduce and Optimise Third-Party Scripts
Third-party tools like chat widgets, ad trackers, or embedded video players can slow down load time and interaction speed. To manage their impact:
Audit and remove unused or duplicate scripts
Load scripts asynchronously where possible
Self-host critical scripts, such as fonts or analytics, for better control
Impact: Improves INP and overall site responsiveness, especially on mobile devices.
Fix 5: Use a Content Delivery Network (CDN) and Browser Caching
Serving your content from geographically closer servers and reducing repeated downloads helps improve page load times. To implement:
Use a CDN like Cloudflare, Fastly, or BunnyCDN
Enable browser caching through server configurations
Compress assets using Gzip or Brotli
Impact: Improves LCP and INP across users in different locations, making performance more consistent.
Each of these fixes can be measured and monitored using Google’s performance tools, which we will cover in the next section.
Which Tools Help You Monitor and Improve Core Web Vitals?
To improve Core Web Vitals, you first need reliable data. Google provides a set of free tools that help track loading speed, layout shifts, and input responsiveness. These tools combine simulated testing with real-world usage data to give you a complete picture of your site’s performance.
Below are the four most effective and distinct tools for monitoring Core Web Vitals:
PageSpeed Insights analyses individual URLs using both lab data (simulated performance) and field data (real user metrics from Chrome). It highlights LCP, CLS, and INP scores separately for mobile and desktop.
Use it to:
Measure Core Web Vitals for any public URL
Identify performance bottlenecks
Prioritise optimisations based on real-user impact
Lighthouse is built into the Chrome browser and provides detailed performance reports. It simulates how your page performs under average network conditions and flags elements that slow down rendering or cause layout shifts.
How to use it:
Open your website in Chrome
Right-click and select Inspect
Navigate to the Lighthouse tab
Choose either mobile or desktop, then run the audit
If your site is verified in Search Console, you can access the Core Web Vitals report, which shows how groups of URLs are performing based on real-world Chrome user data.
Use it to:
Monitor site-wide Core Web Vitals trends
Detect groups of pages failing LCP, CLS, or INP thresholds
CrUX provides anonymised, real-world performance data from Chrome users. It powers the field data seen in tools like PageSpeed Insights and Search Console.
Use it to:
Benchmark your site’s performance against others in your industry
Analyse large-scale trends in user experience
Understand how your site performs across different devices and networks
By using these tools together, you can monitor both individual pages and overall site health, identify what needs fixing, and measure the impact of your optimisations over time.
Growth Plan
Looking to improve your website’s performance across all devices?
Use upGrowth’s Core Web Vitals Audit checklist or connect with our growth team to explore practical improvements for your site.
Core Web Vitals are not just technical scores; they reflect how users experience your website. In 2025, improving these metrics is one of the simplest ways to enhance both your SEO performance and user satisfaction.
Fixes like compressing images, stabilising layouts, and reducing script delays can lead to faster loading times, smoother browsing, and higher search visibility. When these improvements are applied consistently across your site, they also lead to better retention and conversion outcomes.
At upGrowth, we encourage businesses to treat performance optimisation as an ongoing part of digital strategy, not just a one-time fix. Core Web Vitals are a key indicator of how well your website meets user expectations, and fixing them should be a priority for anyone serious about growth.
FAQs
1. How can I quickly improve my website’s Largest Contentful Paint (LCP)? You can improve LCP by compressing large images, using next-gen formats like WebP, and reducing render-blocking scripts that delay content from loading.
2. What are the easiest ways to reduce Cumulative Layout Shift (CLS)? To reduce CLS, always set fixed width and height for images and videos, avoid inserting new content above the fold during load, and minimise dynamic layout changes.
3. How does Interaction to Next Paint (INP) affect user experience and rankings? INP measures how quickly a page responds to user interactions. A high INP score means your site feels unresponsive, which can lower engagement and potentially affect your Google rankings.
4. Can fixing Core Web Vitals boost my position on Google in 2025? Yes. While content remains a core ranking factor, Core Web Vitals influence your site’s page experience score. Better performance can give you an edge in competitive SERPs.
5. Which tools can help monitor and improve Core Web Vitals? Trusted tools include PageSpeed Insights, Lighthouse in Chrome DevTools, Google Search Console, and the Chrome User Experience Report (CrUX).
6. Is there a difference between lab data and field data in Core Web Vitals? Yes. Lab data is based on simulated conditions and helps developers test performance. Field data reflects real-user experience and is what Google uses to evaluate ranking impact.
7. How often should I audit my website’s Core Web Vitals? Monthly audits are ideal for most websites. However, high-traffic or e-commerce sites should monitor them weekly, especially after making design, speed, or layout changes.
8. Can I use ChatGPT to interpret my Core Web Vitals data? Yes. You can input your PageSpeed Insights report into ChatGPT and ask for a simplified explanation or a step-by-step action plan based on your site’s metrics.
9. How can Gen AI tools assist in fixing Core Web Vitals issues? Generative AI can help you identify performance bottlenecks, summarise audit reports, and recommend code optimisations, especially if you integrate it with development workflows or analytics dashboards.
10. Are Core Web Vitals equally important on mobile and desktop? Yes, but Google evaluates performance using mobile-first indexing. This means mobile Core Web Vitals scores typically have a greater influence on your search rankings.
For Curious Minds
Core Web Vitals directly translate key aspects of a user's interaction into quantifiable data, serving as a reliable proxy for their satisfaction. A fast Largest Contentful Paint (LCP) shows content is delivered quickly, while a low Interaction to Next Paint (INP) proves the page responds without lag, directly impacting how usable and professional a site feels. Google prioritizes these signals because they reflect real-world usability, which is a stronger indicator of a quality result than keyword density alone. A technically sound page that users abandon due to frustration is not a good search result. This approach rewards websites that respect a user's time and attention. Metrics like an INP below 200 milliseconds are clear thresholds that separate a smooth experience from a frustrating one, helping Google rank pages that are not just relevant but also accessible and efficient. Explore the full article to see how these metrics combine to form the page experience signal.
The primary difference lies in what they measure: LCP tracks loading speed, while CLS measures visual stability. Largest Contentful Paint (LCP) identifies the single largest image or text block in the viewport and measures how long it takes to render, giving a clear indication of when the user sees the main content. In contrast, Cumulative Layout Shift (CLS) measures the sum of all unexpected layout shifts that occur during the entire lifespan of the page. They work in tandem to define the initial experience: a good LCP makes the site feel fast, while a good CLS makes it feel stable and trustworthy. A site with a fast LCP of 2.1 seconds can still offer a poor experience if its CLS score is high, like 0.2, causing users to mis-click. Google sees both as critical, expecting an LCP under 2.5 seconds and a CLS of less than 0.1 for a good page experience. Learn how to balance both for optimal performance in our detailed analysis.
The shift from FID to INP requires teams to adopt a more holistic view of responsiveness, moving beyond just the first interaction. While FID measured only the delay after a user's first input, Interaction to Next Paint (INP) assesses the latency of all user interactions throughout a page's lifecycle, providing a much more comprehensive picture of its overall responsiveness. Your optimization strategy must now focus on the entire user journey, not just the initial load. To improve a site's INP score, you must:
Break Up Long Tasks: Identify and split long-running JavaScript processes that block the main thread and delay visual updates.
Optimize Event Listeners: Ensure that code tied to clicks, taps, and key presses executes quickly and efficiently.
Reduce Script Bloat: Scrutinize third-party scripts that can compete for resources and slow down interactivity.
Google's target of an INP under 200 milliseconds sets a higher bar for a quality user experience. The full article provides specific techniques for diagnosing and fixing high INP values.
Improving Core Web Vitals serves as a powerful tie-breaker in competitive search results where content quality is similar among top contenders. While Google has not published a direct formula, industry case studies consistently show a correlation between passing the CWV assessment and gaining improved rankings and traffic. For example, when a page moves its Largest Contentful Paint (LCP) from 'needs improvement' to 'good' (under 2.5 seconds), it often sees a measurable lift in average search position for its target keywords. This happens because page experience signals help Google differentiate between two otherwise equally relevant pages. The logic is simple: a faster, more stable, and more responsive page is deemed more helpful to the user. This performance advantage becomes most pronounced in crowded niches like e-commerce or news, where a slight edge in user experience can translate directly to better visibility. Our guide offers more insight into how these metrics influence your competitive standing.
A high Cumulative Layout Shift (CLS) score directly erodes user trust by creating a jarring and unpredictable experience, which is especially damaging on mobile. When buttons, forms, or product images move unexpectedly as the page loads, users may accidentally click the wrong link or lose their place, leading to immediate frustration and a higher likelihood of abandonment. This instability makes a site feel unprofessional and untrustworthy, directly impacting conversions. The most common causes of a CLS score above the recommended 0.1 threshold include:
Images Without Dimensions: Forgetting to specify width and height attributes causes the browser to reflow content once the image loads.
Dynamically Injected Ads: Ad containers that load without a reserved space push existing content down the page.
Web Fonts: A flash of unstyled or invisible text (FOUT/FOIT) can cause significant reflow when the custom font finally renders.
For e-commerce sites, a stable interface is non-negotiable, as even minor frustrations can stop a sale. We cover specific fixes for these issues in the full post.
Improving a slow LCP on an image-heavy blog requires a focused, surgical approach rather than a complete overhaul. You can achieve significant gains by targeting only the LCP element, which is typically the main hero image or a large block of text in the initial viewport. The key is to diagnose the specific element and apply targeted optimizations to speed up its delivery and rendering. Here is a proven four-step process:
1. Identify the LCP Element: Use Google PageSpeed Insights or Chrome DevTools to pinpoint exactly which image or text node is the LCP for a given URL.
2. Optimize the Image: Compress the image without sacrificing quality, convert it to a modern format like WebP or AVIF, and ensure it is sized correctly for the viewport.
3. Prioritize its Loading: Implement a `fetchpriority="high"` attribute on the LCP image tag to signal the browser to load it before other resources.
4. Eliminate Render-Blocking Resources: Ensure that CSS or JavaScript files are not preventing the LCP image from rendering promptly.
This targeted strategy helps you achieve an LCP under 2.5 seconds efficiently. Our guide provides deeper technical details for each step.
Effectively fixing persistent CLS requires a diagnostic process that isolates the source of instability before applying a fix. For publishers, dynamically loaded content like ads and fonts are the most frequent offenders, creating a poor user experience and a CLS score above 0.1. The strategy is to reserve space for dynamic elements before they load, preventing them from disrupting the surrounding content. Follow these steps for a reliable fix:
1. Record a Performance Profile: Use the 'Layout Shifts' track in Chrome DevTools' Performance panel to visually identify what elements are moving during page load.
2. Reserve Space for Ads: For ad slots, define a fixed height and width on the container element (e.g., a `
`) so that a static block of space is held open before the ad script runs.
3. Manage Font Loading: For web fonts, use the CSS `font-display: swap` property to show a system font immediately, minimizing the reflow when the custom font eventually loads.
By creating a stable layout skeleton, you can integrate dynamic content without harming your CLS score. Find more advanced techniques for complex layouts in the complete article.
Core Web Vitals are shifting from a supplementary ranking factor to a foundational element of technical SEO. As Google continues to refine its understanding of user satisfaction, expect these metrics to become more influential and potentially more stringent by 2025. Marketers must move beyond reactive fixes and proactively integrate performance into their content strategy. To prepare for these adjustments, you should:
Integrate CWV Audits: Make performance checks a regular part of your SEO workflow, not an annual task.
Prioritize Mobile Experience: Since Google uses mobile-first indexing, your mobile site’s performance is what primarily determines your ranking, so all optimizations should begin there.
Educate Content Teams: Teach creators about performance implications, such as using uncompressed images or heavy embeds.
The recent replacement of FID with the more comprehensive Interaction to Next Paint (INP) signals that Google is deepening its measurement of user experience. Getting ahead of these trends is explored further in our complete guide.
The adoption of Interaction to Next Paint (INP) as a core metric will force a fundamental shift toward more disciplined JavaScript management. Because INP measures the latency of all interactions, developers can no longer afford to have long-running scripts that block the main thread, as this will directly lead to a poor score. The new standard requires building applications that are consistently responsive, not just fast at the start. This will drive several changes in development practices: developers will more aggressively break down long tasks using techniques like `setTimeout` or the `scheduler.postTask()` API to yield control back to the browser. The scrutiny on third-party scripts will also intensify, with a greater emphasis on loading them asynchronously or deferring them until after key user interactions. Achieving Google's recommended INP of under 200 milliseconds will make efficient script execution a top priority. Our full post details strategies for managing complex scripts in this new context.
The most common mistake is treating Core Web Vitals as a simple technical checklist to satisfy Google, rather than as a proxy for actual user experience. This leads to chasing scores in lab tools while ignoring how real users are affected. A site can have a perfect lab score but still feel slow to a user on a weak mobile connection. A more effective strategy is to shift from a score-chasing mindset to a user-centric one. Instead of just asking, "How do I get my LCP under 2.5 seconds?" you should ask, "What is preventing my users from seeing the main content quickly?" This pivot involves prioritizing real user monitoring (RUM) data over synthetic lab data, understanding the context behind the numbers, and focusing on improvements that deliver a genuinely better and more responsive experience. Our complete guide explains how to combine lab and field data for a more holistic performance plan.
Focusing solely on LCP is a flawed strategy because it only addresses one aspect of user experience: initial load speed. A page can load its main content quickly (good LCP) but still be unusable if elements shift around (bad CLS) or if clicks and taps are unresponsive (bad INP). Google evaluates these three metrics together as part of its page experience signal because they represent distinct, equally important facets of a user's interaction. A truly high-performing site must be fast, stable, and responsive. Addressing all three creates a resilient experience where:
Good LCP provides the perception of speed.
Good CLS (a score less than 0.1) builds trust and prevents user error.
Good INP (under 200 milliseconds) gives the user a feeling of control and efficiency.
Neglecting any one of these pillars leaves a critical gap in the user journey that can lead to frustration and abandonment. Our full guide details how to build a balanced performance profile.
A high INP value creates a tangible and frustrating delay between a user's action and the website's response. For instance, imagine a user on an e-commerce site clicking the "Add to Cart" button. With a poor INP, nothing visually happens for several hundred milliseconds, causing the user to wonder if their click registered. They might click again, leading to duplicate items in the cart, or simply abandon the site assuming it is broken. This perceived lag directly breaks the user's flow and undermines their confidence in the interface. Google has set the threshold for a good INP at under 200 milliseconds because research shows that delays beyond this point are easily noticeable and are perceived as poor performance. A slow response feels like a system failure to the user, making it a critical aspect of page quality. The full article offers more scenarios where high INP can degrade the user experience.
Amol has helped catalyse business growth with his strategic & data-driven methodologies. With a decade of experience in the field of marketing, he has donned multiple hats, from channel optimization, data analytics and creative brand positioning to growth engineering and sales.
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