How to Fix Core Web Vitals Issues: Complete Guide for Better Rankings

Largest Contentful Paint (LCP): The Perception of Speed

LCP measures loading performance. Specifically, it tracks how long it takes for the largest content element within the viewport to become visible to the user. This could be a hero image, a large block of text, or a video. A fast LCP reassures users that the page is useful and loading correctly. A slow LCP creates frustration and increases bounce rates. A key part of site speed optimization is directly targeting this metric when you fix Core Web Vitals issues.

Image optimization techniques to improve Largest Contentful Paint (LCP)

When you fix Core Web Vitals issues related to LCP, you’re directly addressing the user’s first impression of your site’s speed. Many website owners find that learning how to fix Core Web Vitals issues for LCP yields the most immediate improvement in user experience. The process to fix Core Web Vitals issues for LCP typically involves optimizing images, improving server response time, and eliminating render-blocking resources.

First Input Delay (FID): The Measure of Interactivity

FID measures interactivity. It quantifies the time from when a user first interacts with your page (like clicking a button or a link) to when the browser is actually able to respond to that interaction. A long FID makes a site feel sluggish and unresponsive, as if it’s ignoring the user. This is a critical Google ranking factor because it speaks directly to engagement, a key reason to fix Core Web Vitals issues. A user who can’t interact with a page will leave.

JavaScript execution impact on First Input Delay (FID) performance

• Good: Under 100 milliseconds – The response feels instant.
• Needs Improvement: 100-300 milliseconds – A slight, noticeable lag.
• Poor: Over 300 milliseconds – The page feels broken or slow.

Learning how to fix Core Web Vitals issues for FID often involves tackling JavaScript, which can monopolize the browser’s main thread. When you fix Core Web Vitals issues related to FID, you’re creating a more responsive experience that keeps users engaged. Many developers find that the most effective way to fix Core Web Vitals issues for FID is to reduce JavaScript execution time and minimize third-party script impact.

Cumulative Layout Shift (CLS): The Assurance of Stability

CLS measures visual stability. It calculates a score based on how much unexpected layout shift occurs during the entire lifespan of a page. We’ve all experienced this: you go to click a button, and just as you’re about to tap, an ad loads above it and you end up clicking something else. This is not only frustrating but can also lead to accidental clicks and a terrible user experience. The page experience update heavily penalizes sites with poor CLS, making it crucial to fix Core Web Vitals issues related to stability.

Visual example of Cumulative Layout Shift (CLS) affecting user experience

Understanding the trio of LCP FID CLS is the foundation of any performance strategy. They work together to create a fast, responsive, and stable experience. When you fix Core Web Vitals issues across all three metrics, you create a holistic improvement that users will notice immediately. Many site owners discover that once they learn how to fix Core Web Vitals issues for all three metrics, their overall site performance improves dramatically.

Must-Have Diagnostic Tools

Google PageSpeed Insights report with Core Web Vitals analysis

When you fix Core Web Vitals issues, you need to measure before and after to validate your efforts. These tools provide the data you need to make informed decisions about your optimization strategy. The journey to fix Core Web Vitals issues always begins with accurate measurement and diagnosis.

Fixing LCP (Largest Contentful Paint)

To improve LCP, you need to optimize your loading performance. The goal is to get the most important content on the screen as quickly as possible. This is a critical part of learning how to fix Core Web Vitals issues for better loading performance.

1. Optimize Your Images

Images are the most common cause of slow LCP. Follow these steps to fix Core Web Vitals issues related to images:

• Compress Images: Use tools like TinyPNG or Squoosh to reduce file size without significant quality loss.
• Use Next-Gen Formats: Convert images to WebP, which offers better compression than JPEG or PNG. Always provide a fallback for older browsers.
• Implement Responsive Images: Use the <srcset> attribute to serve different sized images based on the user’s device.
• Lazy Load Images: Add loading="lazy" to images that are below the fold. This tells the browser not to load them until they’re needed.

2. Improve Server Response Time (TTFB)

Your server’s Time to First Byte (TTFB) is the foundation of LCP. If your server is slow, nothing else you do will matter much. To fix Core Web Vitals issues related to server response:

• Upgrade Your Hosting: Shared hosting is often slow. Consider upgrading to managed WordPress hosting, VPS, or cloud hosting.
• Enable Server-Side Caching: Use caching mechanisms like Varnish or built-in host caching to serve pages instantly.
• Use a CDN: A Content Delivery Network (CDN) like Cloudflare stores copies of your site on servers around the world, reducing latency for all users.

3. Eliminate Render-Blocking Resources

CSS and JavaScript can block your page from rendering. To fix Core Web Vitals issues here, you need to be strategic.

• Minify CSS and JS: Remove unnecessary characters (spaces, comments) from your code files.
• Defer Non-Critical JavaScript: Use the defer or async attributes on script tags so they don’t block rendering.
• Inline Critical CSS: Identify the CSS needed for above-the-fold content and place it directly in a <style> tag in your HTML <head>.

Fixing FID (First Input Delay)

FID is all about interactivity. A high FID means the browser is busy doing other things (usually executing JavaScript) when the user tries to interact with the page. To fix Core Web Vitals issues related to FID, you need to tame your JavaScript and improve interactivity.

1. Optimize JavaScript Execution

The browser’s main thread can only do one thing at a time. Long JavaScript tasks block it from responding to user input. When you fix Core Web Vitals issues related to JavaScript:

• Code Splitting: Break up your JavaScript bundles into smaller pieces. Only load the code that’s necessary for the current page.
• Remove Unused JavaScript: Use tools like Chrome DevTools’ Coverage tab to find and remove code that you’re not using.
• Use Web Workers: For heavy computations, move them off the main thread to a Web Worker so the UI remains responsive.

2. Reduce Third-Party Script Impact

Third-party scripts for analytics, ads, and chat widgets are notorious for causing FID issues. To fix Core Web Vitals issues from third-party scripts:

• Audit Your Scripts: Remove any third-party scripts that aren’t providing clear value.
• Load Scripts Asynchronously: Use the async attribute to prevent scripts from blocking the page.
• Self-Host Scripts: If possible, host critical third-party scripts on your own server to have more control over how they’re loaded.

Fixing CLS (Cumulative Layout Shift)

CLS is about stability. The key to a good CLS score is ensuring that your page layout doesn’t change unexpectedly. This is often the easiest metric to fix Core Web Vitals issues for, with a big impact on user experience.

1. Reserve Space for Dynamic Content

The browser needs to know how much space to allocate for elements before they load. To fix Core Web Vitals issues related to layout shift:

• Always Include Dimensions: Add width and height attributes to all your <img> and <video> tags.
• Use Aspect Ratios: For responsive images, use CSS aspect-ratio boxes to reserve the correct space.
• Reserve Space for Ads: If you have ad slots, style the container with a fixed height and width so the page doesn’t shift when the ad loads.

2. Optimize Font Loading

Web fonts can cause significant layout shift. When a custom font loads, it can change the size of text, pushing other elements around. To fix Core Web Vitals issues related to fonts:

• Use font-display: swap; This CSS descriptor tells the browser to display a fallback system font immediately, then “swap” in the custom font once it loads. This prevents invisible text.
• Preload Critical Fonts: Use <link rel="preload" as="font"> for your most important fonts to load them faster.
• Match Font Sizes: Ensure your fallback system fonts have a similar size and line-height to your custom web fonts to minimize shift.

WordPress Performance Plugins

If you’re on WordPress, you have a huge advantage. The plugin ecosystem can handle most of the heavy lifting for you. These tools make it easy to fix Core Web Vitals issues without technical knowledge, a key part of our guide on how to fix Core Web Vitals issues. For a comprehensive solution, consider our specialized website speed optimization plugin that addresses all three Core Web Vitals metrics.

Installing and configuring one of these plugins is often the single biggest step a non-technical user can take to fix Core Web Vitals issues. The journey to fix Core Web Vitals issues doesn’t have to be complicated, especially with the right tools.

Hosting Solutions

Your hosting is the bedrock of your site’s performance. A cheap, slow host will undermine all your other efforts. When you fix Core Web Vitals issues related to hosting, you are addressing the foundation of your site’s speed.

• Shared Hosting: Cheapest option, but you share resources with hundreds of other sites. Not recommended for performance.
• Managed WordPress Hosting: Optimized specifically for WordPress. Includes caching, security, and support. A great choice for most businesses.
• Cloud Hosting: Scalable and reliable, but can be more complex to manage. Options include DigitalOcean, Vultr, and AWS Lightsail.

Many businesses find that simply upgrading their hosting is the fastest way to fix Core Web Vitals issues without any technical changes to their website.

CDN Implementation

A Content Delivery Network is a non-technical way to get a huge performance boost. Services like Cloudflare have free plans that are incredibly easy to set up. You simply sign up, point your domain’s nameservers to Cloudflare, and they handle the rest. This is a cornerstone of site speed optimization that anyone can implement to fix Core Web Vitals issues and improve global performance.

For many site owners, implementing a CDN is the first step in their journey to fix Core Web Vitals issues. It’s a simple change that can have a dramatic impact on all three Core Web Vitals metrics.