An Overview Of Core Web Vitals In 2025

2025 is just the same for SEOs; however, in 2025, Core Web Vitals have emphasized certain key metrics and most of it is about user experience. The first one is the Larget Contentful Paint (LCP), which measures the perceived load speed of a page. In simpler words, the time it takes for the largest content element above the fold to become visible to users is determined in this step. 

Ideally, your LCP should be under 2.5 seconds, and if your score is below this number, you can try optimizing image loading (minimizing the image size), minifying CSS and JavaScript files, and reducing server response times. Scoring for under 2.5 seconds means the main content of the page will load quickly and appear within seconds. 

Cumulative Layout Shift (CLS) is a metric to measure the visual stability of a page. Usually, the websites have elements with animation effects or are dynamic, so they might need visual stability. For example, we don’t want unexpected shifts or movements on the screen during loading because it gets jarring and frustrating. 

Therefore, it is recommended that your CLS should be under 0.1 seconds. This will ensure a stable and visually consistent page, reduce the likelihood of accidental clicks and improve user satisfaction. One of the best practices to improve your CLS score is to use placeholders or aspect-ratio boxes to reserve space for images and ads before they load, preventing layout shifts.

Next comes the Interaction to Next Paint (INP) metric, which measures the responsiveness of a website to user interactions. In simpler words, it captures the time it takes for the browser to respond to user inputs, such as clicks or taps, and render the next frame on the screen.

Ideally, the INP should be less than or max at 200 milliseconds. I always focus on optimizing JavaScript execution to reduce the time it takes to process user interactions and minimize layout shifts for a smooth and enjoyable user experience. 

Now, let me tell you how you can optimize your website for Core Web Vitals. I have discussed some points above, but let me shed light on all the strategies in detail. 

Important Optimizations For Core Web Vitals in 2025

First of all, you need to get a comprehensive core web vitals assessment and check what aspect of your website needs improvement. Here is what you need to do:

Step #1. Improve LCP Score 

Image Optimization

Image Optimization is the first step you need to improve your website’s LCP score. 

Image Formatting

• Webp – This modern format offers better compression than JPEG, resulting in smaller file sizes and faster loading times. Most modern browsers support WebP.
• AVIF – An even newer format that provides even higher compression rates than WebP, but with slightly less browser support. Consider using it for images where quality is less critical.
• Tools – Use online tools like Cloudinary or image optimization plugins within your CMS (like ShortPixel for WordPress) to easily convert images to WebP or AVIF.

Image Resizing and Compression

• Resize images to their actual dimensions on the page. Avoid uploading oversized images.
• Use tools like ImageOptim (macOS), TinyPNG, or online services like Cloudinary to compress images without noticeable quality loss. Aim for a balance between image quality and file size.

Lazy Loading

• Use JavaScript libraries like lazysizes or built-in browser support (if available) to delay the loading of images that are not initially visible on the screen.
• Display low-resolution placeholders or blurred versions of images while they load to improve perceived performance.

Prioritizing LCP Images with ‘fetchpriority’

• Determine the largest image that contributes most to the initial visual content of your page.
• Add the fetchpriority=”high” attribute to the <img> tag of your LCP image. This signals the browser to prioritize the download of this image.

Server Side Rendering (SSR) 

The next step is Server Side Rendering (SSR) to optimize LCP. Instead of sending a blank HTML page to the browser and then loading JavaScript to dynamically populate it, SSR renders the HTML on the server before sending it to the browser. Utilize frameworks like Next.js (React), Nuxt.js (Vue.js), or Gatsby (React) that support SSR. If using a different framework, you can implement SSR manually, but it requires more technical expertise.

JavaScript Loading

The first thing you have to do is defer non-critical Java script. This involves determining which JavaScript files are not essential for the initial rendering of the page (e.g., analytics, social media widgets). Or, you can add the defer attribute to scripts that can be loaded after the HTML has been parsed. Use async for scripts that do not affect the initial page rendering and can be loaded concurrently.

Besides, you can use the code splitting method, which breaks down large JavaScript files into smaller, more manageable chunks (bundles). Or you can use tools like Webpack or Rollup to dynamically load only the JavaScript code required for the specific parts of the page that are currently visible to the user.

Lastly, minimizing JavaScript bundle size would help. You can either use tools like Terser or UglifyJS to minify your JavaScript code by removing unnecessary characters (whitespace, comments) without affecting functionality. Or utilize tree-shaking to remove unused code from your JavaScript bundles, further reducing their size.

Summing Up

Core Web Vitals remain a crucial factor in determining user experience and search engine rankings in 2025 and beyond. As user expectations continue to evolve and technology advances, the importance of providing a fast, smooth, and responsive web experience will only increase.

Continuous monitoring of Core Web Vitals metrics using tools like Google Search Console and PageSpeed Insights is essential to identify areas for improvement. Regularly review and update your website’s code and content to ensure optimal performance.

While Core Web Vitals currently focus on loading performance, visual stability, and interactivity, the future may see the inclusion of new metrics that address other aspects of user experience, such as accessibility and sustainability.

To achieve and maintain top Core Web Vitals scores, consider partnering with Emerging Software, a digital marketing agency specializing in website optimization and performance improvement. Our expert team can help you implement best practices, identify and resolve performance bottlenecks, and ensure your website delivers a seamless user experience.