Are you looking for ways to improve your website’s loading speed and user experience? This comprehensive guide will help you diagnose and improve core web vitals. You’ll learn how to measure web vitals, optimise for performance, and improve Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift. With these techniques, you’ll be able to monitor and track your website’s success.

Key Takeaways

  • Measuring and tracking web vitals is essential for optimising website performance and user experience.
  • Core Web Vitals, including Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift, are key metrics to focus on.
  • Optimising images, minimising JavaScript, and reducing page redirects are effective techniques for improving web vitals.
  • Diagnosing and addressing issues related to Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift will significantly enhance website performance.

Measuring Web Vitals

Your website’s performance can be measured by its Core Web Vitals. These are metrics that measure the user experience on your website, such as loading performance, interactivity, and visual stability. To measure these metrics, you’ll need to use a variety of tools, such as the Chrome User Experience Report, PageSpeed Insights, and Lighthouse. Each tool provides a unique set of data points, so it’s important to use all of them to get a comprehensive picture of your website’s performance.

In addition to these tools, there are also techniques you can use to track your website’s performance. For example, you can set up a test environment to measure the loading times and overall performance of your website. You can also use Google Analytics to track user engagement and conversion rates. By combining these tools and techniques, you can get an accurate picture of your website’s performance and identify areas for improvement.

Finally, you should regularly review your website’s performance data and make adjustments accordingly. You should also ensure that any changes you make are properly tested and monitored. This way, you can make sure that your website is always performing optimally.

These are the steps you should take to measure and improve your website’s Core Web Vitals. By using the right tools and techniques, you can ensure that your website is always delivering an outstanding user experience.

Core Web Vitals Overview

Building on the tools and techniques discussed previously, this subtopic will provide an overview of Core Web Vitals and their importance to website performance. Core Web Vitals are a set of metrics that measure the speed, responsiveness, and visual stability of a website. These metrics provide an indication of how users experience a website, and they are essential for optimising the user experience.

The Core Web Vitals measure three distinct areas of website performance: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). LCP measures the amount of time it takes for the main content of a page to load. FID measures the responsiveness of the page by measuring the amount of time it takes between a user’s action and the browser’s response. CLS measures the amount of visual instability on a page.

These metrics are essential for measuring website performance because they provide an indication of how users experience a website. By understanding how users experience a website, website owners and developers can make changes to improve the user experience. This can include optimising images, minimising JavaScript, and reducing page redirects.

Ultimately, Core Web Vitals provide an indication of how users experience a website. By understanding and optimising these metrics, website owners and developers can ensure that their website is providing the best possible user experience.

Optimising for Performance

Once you have an understanding of Core Web Vitals, it is important to optimise your website for performance. This includes both improving performance metrics, such as First Contentful Paint (FCP), and reducing the frequency of low-optimised page experiences. To do this, you need to use the right tools and techniques.

First, you should use web performance tools that measure the Core Web Vitals and other performance metrics. These tools will help you to identify areas of potential improvement, such as reducing JavaScript blocking time or optimising image sizes. Additionally, you should use tools to monitor the performance of your website in real-time, so you can quickly detect and address any performance issues that arise.

Next, it is important to use techniques to improve the performance of your page. This includes optimising images, reducing JavaScript blocking time, and minifying HTML, CSS, and JavaScript. Additionally, you should use caching techniques to help reduce page load time and make pages load faster.

Finally, you should use techniques to improve the user experience. This includes ensuring that the page is responsive and mobile-friendly, and that the page is properly structured for easy navigation. You should also ensure that the page is optimised for search engine optimization (SEO) and that the content is engaging and relevant to the target audience.

Improving Largest Contentful Paint

Continuing on from optimising page performance, the next step is to focus on improving Largest Contentful Paint (LCP) metrics. LCP measures how long it takes for the main element of a page to load, and is an important factor in a page’s overall performance. To diagnose and improve LCP, it’s important to take a look at the page’s resources, such as images, videos, fonts, and scripts. If any of these resources are too large, they can slow the page’s loading time and cause poor LCP scores. To improve LCP, prioritise the resources that are most important to the page and reduce their file size. You can also consider lazy loading, which is a technique where resources are only loaded when they’re needed. This can help reduce initial page load time and improve LCP scores. Additionally, consider optimising the server’s response time, which can help reduce the time it takes for the page’s main element to load. Finally, consider using a caching strategy to reduce the amount of data that needs to be loaded when a page is accessed. With the right tools and techniques, you can diagnose and improve LCP and help your page perform better.

Optimising First Input Delay

Optimising First Input Delay involves reducing the time it takes for a user to interact with a page. This is an important metric, as it measures how quickly a user can begin interacting with the page’s content. Here are four key steps to take when diagnosing and improving First Input Delay:

  1. Review the page’s JavaScript, and identify any scripts that are blocking the main thread.
  2. Minimise any third-party scripts that are used on the page.
  3. Take advantage of the browser’s idle time to preload resources.
  4. Use code-splitting to reduce the amount of JavaScript code that needs to be downloaded.

When optimising First Input Delay, it’s important to keep in mind that the goal is to reduce the time it takes for a user to interact with the page. This isn’t the same as reducing page load time, which is why optimising First Input Delay often requires different techniques. For example, preloading resources can help improve First Input Delay without significantly reducing page load time.

In addition to the techniques mentioned above, it’s important to take a holistic approach to improving First Input Delay. This means keeping an eye on other performance metrics such as Time to Interactive and Total Blocking Time, as they can have a negative impact on First Input Delay. In addition, it’s important to stay up-to-date on the latest browser features that can help improve First Input Delay, such as the Performance Timing API.

Improving Cumulative Layout Shift

When it comes to improving Cumulative Layout Shift, your goal is to ensure that content remains stable as a user interacts with your page. This is measured by the amount of unexpected layout shifts that occur while a page is loading. The most common cause of poor Cumulative Layout Shift (CLS) scores is the lack of size and position attributes on page elements. This can lead to the elements shifting around during page load, resulting in a bad user experience when they are trying to interact with the page.

In order to improve CLS scores, you need to first identify which elements are causing shifts. There are various tools available to help you with this. You can use the Chrome DevTools or Lighthouse to identify which elements are causing shifts, and then use the PageSpeed Insights tool to identify which elements need to be optimised.

Once you have identified the elements that are causing shifts, it’s important to make sure they have size and position attributes. This can be done by adding width and height attributes to images and by adding a position attribute to any element that is not already in a fixed position on the page.

It’s also important to ensure that any animation or interaction that causes a layout shift is properly communicated to the user. This can be done with a visual cue such as an arrow or a message informing the user of what is about to happen. This will help prevent unexpected layout shifts and give the user an improved experience.

Finally, if you have any third-party scripts or ads running on your page, it’s important to check that they are not causing any unexpected layout shifts. This can be done by testing the page in different browsers and devices, and making sure that the elements remain in the same place throughout the loading process.

Improving CLS scores can take some time and effort, but it’s worth it to ensure that your page is providing a good user experience. By following the steps outlined above, you should be able to significantly improve your CLS scores and give your visitors a better experience.

Monitoring Results

Once you’ve implemented the necessary changes to improve your Core Web Vitals, it’s important to monitor the results of those changes. To do this, you’ll need to:

  1. Set up tracking for the Core Web Vitals metrics in a tool such as Google Search Console or PageSpeed Insights.
  2. Analyse the data to determine if any changes you’ve made have improved your performance.
  3. Take note of any significant changes and investigate what caused them.
  4. Develop a plan for further optimization if needed.

Monitoring the performance of your Core Web Vitals over time is an essential part of ensuring your website is running optimally. By tracking changes in your metrics, you can quickly identify when something is not working as it should and take action to fix it. It’s important to keep an eye on the data and look for any significant changes that could indicate a potential issue. If you find that something has gone wrong, you can then investigate further to determine the cause and take steps to fix it.

You can also use the monitoring data to track the success of your optimization efforts. By comparing the data before and after you make any changes, you can quickly determine if the changes you’ve made have had a positive effect on your Core Web Vitals. If they have, you can then take steps to further optimise your website and improve its performance.


You’ve made it to the end of the comprehensive guide to diagnosing and improving Core Web Vitals. You now have the tools and techniques to measure your web vitals, optimise for performance, and improve LCP, FID, and CLS. By following the steps outlined in this guide, you’ll be able to monitor the results and ensure a superior user experience for your website visitors.