How to Optimize Your Website for Core Web Vitals and Boost Your SEO Rankings

Core Web Vitals are a set of performance metrics that measure the quality of user experience on a web page. They are part of Google’s page experience ranking factors, which means they can affect your organic search rankings and user engagement.

The three metrics that make up Core Web Vitals are: Largest Contentful Paint (LCP), which measures how fast the largest content element on the page loads; First Input Delay (FID), which measures how responsive and interactive the page is; and Cumulative Layout Shift (CLS), which measures how stable the page layout is.

This blog post will provide you with practical tips on how to optimize your website for Core Web Vitals and boost your SEO rankings.

What are Core Web Vitals and How Do They Affect SEO Rankings?

Core Web Vitals as mentioned before are sets of performance metrics that measure the quality of user experience on a web page. They are part of Google’s page experience ranking factors, which are a group of signals that Google uses to evaluate how user-friendly and satisfying a web page is.

These ranking factors can affect your organic search rankings and user engagement, which are crucial for your online success.

Largest Contentful Paint (LCP)

This is a user experience (UX) metric that measures how fast the largest content element on a web page loads and is visible to the user.

A good LCP value is less than 2.5 seconds, which means that the main content of the page is likely loaded and useful for the user. LCP can be affected by factors such as network speed, server response time, image optimization, and code efficiency.

First Input Delay (FID)

This is a user experience (UX) metric that measures how fast the browser can respond to a user’s interaction with a web page.

A good FID value is less than 100 milliseconds, which means that the page is responsive and interactive. FID can be affected by factors such as network speed, server response time, JavaScript execution, and code efficiency.

Cumulative Layout Shift (CLS)

This is a user experience (UX) metric that measures how much the layout of a web page shifts during its loading or interaction.

A good CLS score is less than 0.1, which means that the page is stable and does not move unexpectedly. CLS can be affected by factors such as images, videos, fonts, ads, or widgets that change their size or position without reserving enough space.

To measure and improve on your website LCP, FID, and CLS, you can use tools such as Google Search Console, PageSpeed Insights, Lighthouse, and web.dev.

Some largest websites with millions of monthly traffic that have improved their Core Web Vitals scores and reported positive outcomes.

Pinterest, one of the largest picture search engines, reduced its LCP by 40%, its FID by 60%, and its CLS by 44%, resulting in an increase of organic traffic by 15% and sign-ups by 50%.

The Guardian, which improved its LCP by 80%, its FID by 47%, and its CLS by 16%, resulted in an increase of page views per session by 7.5% and ad impressions by 10%.

Another most popular website, CNET, which improved its LCP by 55%, its FID by 65%, and its CLS by 50%, also resulted in an increase of page views by 9% and revenue by 10%.

How to Measure and Analyze Your Core Web Vitals Scores

To optimize your website for CWV, you need to measure and analyze your CWV scores and identify the areas that need improvement. Let’s introduce some of the free and accurate tools and methods that can help you do that. We will also explain how to interpret the results you get from these tools.

1. Google Search Console

Google Search Console (GSC) is a free tool that helps you monitor and improve your website’s performance and visibility on Google Search. It provides you with a Core Web Vitals report that shows you how your web pages perform based on real-world usage data from Chrome users.

The report categorizes your web pages into three groups based on their CWV scores: Good, Needs improvement, and Poor. It also shows you the distribution of your pages by metric and by device type (mobile or desktop).

To access the report, you need to verify your website ownership on GSC and navigate to Enhancements > Core Web Vitals.

The report helps you identify the pages that need attention and prioritize your optimization efforts. You can also drill down into each page group and see the specific URLs that fall into that category. You can also filter the report by status, metric, or URL to narrow down your analysis.

2. PageSpeed Insights

PageSpeed Insights (PSI) is a free tool that analyzes the performance and usability of your web pages and provides you with suggestions on how to improve them. It uses data from both Lighthouse and Chrome User Experience Report (CrUX) to generate a PageSpeed score and a Core Web Vitals assessment for each page.

The PageSpeed score ranges from 0 to 100 and reflects how well the page follows the web performance best practices. A score of 90 or above is considered fast, 50 to 89 is considered moderate, and below 50 is considered slow .

The Core Web Vitals assessment shows you how your page performs based on the real-world data from CrUX. It also shows you the thresholds and the field data for each metric. The assessment can be either Passed or Not passed, depending on whether the page meets the recommended criteria for all three metrics.

To use PSI, you need to enter the URL of the page you want to analyze and choose the device type (mobile or desktop). You can also compare your page with your competitors’ pages by entering multiple URLs.

The report provides you with a summary of the performance and usability of your page, as well as detailed information on the opportunities and diagnostics for each metric. You can also see the lab data from Lighthouse, which simulates how the page loads in a controlled environment. The lab data can help you debug the performance issues and validate the improvements.

3. Lighthouse

Lighthouse is an open-source tool that audits the quality and performance of your web pages and provides you with a comprehensive report and actionable recommendations. It measures your page against a set of audits that cover different aspects of web development, such as performance, accessibility, best practices, SEO, and progressive web apps (PWA).

One of the categories that Lighthouse audits is Performance, which includes the CWV metrics as well as other metrics that are relevant for web performance, such as First Contentful Paint (FCP), Time to Interactive (TTI), Speed Index (SI), and Total Blocking Time (TBT).

Lighthouse generates a Performance score that ranges from 0 to 100 and reflects how well the page performs on each audit. A score of 90 or above is considered good, 50 to 89 is considered needs improvement, and below 50 is considered poor.

To use Lighthouse, you can either install it as a Chrome extension, run it from the Chrome DevTools, or use it as a Node module or a CLI tool. You can also customize the settings and the audits that you want to run.

The report provides you with a summary of the performance and quality of your page, as well as detailed information on the metrics, the audits, and the opportunities and diagnostics for each category. You can also see the screenshots and the trace of how the page loads over time.

4. Chrome DevTools

Chrome DevTools Performance panel overall performance

Chrome DevTools is a set of web developer tools that are built into the Google Chrome browser. It helps you inspect, debug, and optimize your web pages and applications. It offers a variety of features and panels that cover different aspects of web development, such as elements, console, sources, network, performance, memory, application, security, and more.

One of the panels that Chrome DevTools provides is the Performance panel, which allows you to record and analyze the performance of your web page as it loads and runs. It shows you a performance timeline that visualizes the events and activities that happen on the page, such as scripting, rendering, painting, and loading.

The performance timeline also shows you the CWV metrics and their values, as well as other performance metrics, such as FCP, TTI, SI, and TBT. You can also see the screenshots and the filmstrip of how the page looks at different points in time.

To use the Performance panel, you need to open Chrome DevTools, go to the Performance tab, and click the record button. You can also customize the settings and the features that you want to capture, such as screenshots, memory, and network.

The panel provides you with a summary of the performance and the metrics of your page, as well as detailed information on the timeline, the events, and the frames. You can also zoom in and out, filter and search, and select and inspect the elements and the activities that happen on the page.

5. web.dev

web.dev is a website that provides you with guidance and resources on how to build modern and high-quality web experiences. It covers topics such as performance, accessibility, SEO, PWA, security, and more.

One of the features that web.dev offers is the Measure tool, which allows you to measure and analyze the performance and the quality of your web pages. It uses Lighthouse to generate a report and a score for each category, as well as suggestions on how to improve them.

The Measure tool also shows you the CWV metrics and their values, as well as other performance metrics, such as FCP, TTI, SI, and TBT. You can also see the field data from CrUX, which shows you how your page performs based on the real-world data from Chrome users.

To use the Measure tool, you need to enter the URL of the page you want to measure and click the Run audit button. You can also compare your page with your competitors’ pages by entering multiple URLs.

The tool provides you with a summary of the performance and the quality of your page, as well as detailed information on the metrics, the audits, and the opportunities and diagnostics for each category. You can also see the lab data and the field data for each metric.

How to Optimize Your Website for Core Web Vitals

To optimize your website for CWV, you need to follow some best practices and tips on how to improve your website for each of the CWV metrics. So, let’s provide you with a list of optimization techniques for LCP, FID, and CLS.

How to Optimize Your Website for LCP

LCP measures how fast the largest content element on the page loads and is visible to the user. A good LCP value is less than 2.5 seconds, which means that the main content of the page is likely loaded and useful for the user. As mentioned before, LCP can be affected by factors such as network speed, server response time, image optimization, and code efficiency.

Here are some ways to reduce the loading time of the largest content element on the page and improve your LCP score:

Use lazy loading: Lazy loading is a technique that delays the loading of images or other resources that are not visible on the screen until the user scrolls to them. This can reduce the initial loading time and bandwidth consumption of the page, and improve the LCP score.
Optimize your images: Images are often the largest content element on the page, and they can have a significant impact on the LCP score. You can optimize your images by using the appropriate format, size, quality, and compression for your images. You can also use responsive images to serve different versions of your images based on the device width and pixel density.
Minify your CSS: CSS is the code that styles your web page, and it can affect the LCP score by blocking the rendering of the page until it is downloaded and parsed. You can minify your CSS by removing unnecessary spaces, comments, and characters from your code, and reducing the file size and the number of requests.
Use a CDN: A CDN (Content Delivery Network) is a network of servers that deliver your web content to the users based on their geographic location, which can reduce the latency and improve the loading speed of your web page. You can use a CDN to host your static assets, such as images, CSS, JavaScript, fonts, and videos, and improve your LCP score.

How to Optimize Your Website for FID

FID measures how fast the browser can respond to a user’s interaction with a web page, such as clicking a button, entering text, or scrolling. A good FID value is less than 100 milliseconds, which means that the page is responsive and interactive. FID can be affected by factors such as network speed, server response time, JavaScript execution, and code efficiency.

Here are some ways to improve the responsiveness and interactivity of the page and improve your FID score:

Use browser caching: Browser caching is a technique that stores a copy of your web content on the user’s browser, which can reduce the loading time and the number of requests of the page, and improve the FID score.
Remove unused JavaScript: JavaScript is the code that adds functionality and interactivity to your web page, and it can affect the FID score by blocking the main thread and delaying the user input. You can remove unused JavaScript by eliminating the code that is not needed or used on your page, and reducing the file size and the number of requests.
Break up long tasks: Long tasks are tasks that take more than 50 milliseconds to complete on the main thread, which can block the user input and degrade the FID score. You can break up long tasks by splitting them into smaller chunks, using web workers to run them in the background, or using requestAnimationFrame to schedule them in the browser.

How to Optimize Your Website for CLS

CLS measures how much the layout of a web page shifts during its loading or interaction. A good CLS score is less than 0.1, which means that the page is stable and does not move unexpectedly. CLS can be affected by factors such as images, videos, fonts, ads, or widgets that change their size or position without reserving enough space.

Here are some ways to prevent unexpected layout shifts on the page and improve your CLS score:

Specify dimensions for images and videos: Images and videos are common elements that can cause layout shifts on the page, especially if they are loaded after the initial render. To avoid this, you should specify the width and height attributes for your `<img>` and `<video>` tags, or use CSS to define the aspect ratio and the size of the elements. This way, the browser can allocate the appropriate space for the elements before they are loaded, and prevent them from pushing or moving other elements on the page.
Avoid inserting content above existing content: Inserting content above existing content can cause layout shifts on the page, especially if the content is dynamic or loaded asynchronously. For example, if you insert an ad, a banner, or a notification above the main content of the page, it can push the content down and disrupt the user’s reading or interaction. To avoid this, you should reserve enough space for the content that you want to insert, or place it below or beside the existing content.
Use web fonts that match the fallback fonts: Web fonts are custom fonts that are downloaded from the web and applied to your web page. They can enhance the appearance and the readability of your web page, but they can also cause layout shifts if they are loaded after the initial render. To avoid this, you should use web fonts that match the fallback fonts that are available on the user’s device, or use font-display to control how the web fonts are rendered. This way, the browser can render the text with the fallback fonts until the web fonts are loaded, and prevent them from changing the size or the shape of the text.

Final Thoughts

Optimizing your website for Core Web Vitals is not only beneficial for your SEO rankings, but also for your overall user experience.

Following the best practices and tips we’ve shared in this blog post, can help improve your LCP, FID, and CLS scores, and provide a fast, responsive, and stable web page for your visitors and customers. This can lead to increased traffic, conversions, and revenue for your website.

We hope you found this blog post helpful and informative. If you have any feedback, questions, or results to share, please leave a comment below or contact us. We would love to hear from you and see how you optimized your website for Core Web Vitals.