Core Web Vitals are essential for modern websites aiming to rank well on search engines and provide an outstanding user experience. In this article, we’ll break down what Core Web Vitals are, why they matter, and how you can optimize your website to enhance SEO and delight users.
What Are Core Web Vitals?
Core Web Vitals are a set of metrics introduced by Google to measure the quality of user experience on a website.
These metrics focus on three key aspects of web performance: loading speed, interactivity, and visual stability.
Google considers Core Web Vitals a critical part of its page experience ranking signals, which means they directly impact how your website ranks in search results. By optimizing these metrics, you ensure a smoother experience for users and improve your chances of higher rankings.
The three Core Web Vitals are:
- Largest Contentful Paint (LCP): Measures loading performance.
- Interaction to Next Paint (INP): Measures responsiveness to user interactions.
- Cumulative Layout Shift (CLS): Measures visual stability.
Improving these three metrics ensures your website is fast, responsive, and stable—factors that directly impact how users perceive your site and whether they’ll stay or leave.
To check your site’s Core Web Vitals, go to the “Experience” section in your Google Search Console account. This is where you can see how your site performs in terms of user experience.
You can also check your Core Web Vitals using tools like Google’s PageSpeed Insights or Semrush Site Audit.
Note: A free Semrush account lets you scan up to 100 URLs with Site Audit. To help find issues with your site’s Core Web Vitals and other aspects of your technical SEO.
Why Are Core Web Vitals Important?
Your website’s performance in Core Web Vitals directly affects both user experience and your chances of ranking higher on Google.
A fast, smooth, and enjoyable website experience is what users expect, and Google rewards pages that meet these expectations.
Google’s page experience ranking system includes several important factors, such as:
- HTTPS (for secure connections)
- Mobile-friendliness
- No intrusive pop-ups
- Safe browsing (no malware)
Core Web Vitals play a key role in this system.
However, it’s important to understand that a great user experience alone won’t automatically push your site to the top of search results. Google uses many ranking factors, and Core Web Vitals are just one piece of the puzzle.
Below, I’m going to break down all three Core Web Vitals. And show you how to improve each of them.
Largest Contentful Paint (LCP)
LCP measures how quickly a webpage loads from the user’s point of view.
It focuses on the time it takes for the largest visible element on the page, like a big image or a text block, to fully load. The faster this happens, the better the user experience!
You can check your LCP score using PageSpeed Insights.
Which is helpful. Especially when it comes to spotting areas to improve.
To get a clearer picture of your LCP, I recommend checking the data in your Google Search Console.
Why?
Because, like Google PageSpeed Insights, the data in Search Console comes from the Chrome User Experience Report.
But unlike PageSpeed Insights, you can see LCP performance for your entire site, not just individual pages. This gives you a broader view, with URLs categorized as Good, Needs Improvement, or Poor.
Google has specific LCP guidelines, and they sort the speed into three categories: Good, Needs Improvement, and Poor. They use similar categories for all three Core Web Vitals, but each has its own set of guidelines.
In simple terms, you should aim for your site’s LCP to load in under 2.5 seconds on every page.
This can be tricky, especially for pages with lots of elements or large images at the top. High-resolution images, in particular, can make it harder to meet that speed goal.
Note: Focus on content quality and user experience, not just Core Web Vitals scores.
Here are a few steps you can take to boost your site’s LCP:
- Remove unnecessary third-party scripts: Research shows that each extra script can slow down your page by 34 milliseconds.
- Upgrade your hosting: A better web host can speed up your site, helping reduce LCP times.
- Avoid lazy loading images above the fold: While lazy loading can improve image loading, applying it to images above the fold may actually slow down LCP.
- Remove large elements above the fold: Try removing heavy images or features from the top of your page to make it load faster.
- Minify your CSS: Large CSS files can slow down your LCP, so make sure to streamline them for better performance.
Interaction to Next Paint (INP)
Let’s dive into the second Core Web Vital: Interaction to Next Paint (INP).
INP measures how quickly your website responds after a user interacts with it—like clicking a button, tapping a link, or selecting an option from a menu—once the page has finished loading.
This metric replaced First Input Delay (FID) in 2024 and focuses on how responsive your page is after it’s fully loaded. It’s a more reliable way to gauge how smoothly users can interact with your page.
Some examples of interactions include:
- Selecting an option from a menu
- Clicking a button to submit a form
- Opening a mobile navigation menu
Just like with LCP, Google has set specific guidelines for what counts as a good INP time.
Ideally, you want your INP time to be under 200 milliseconds. If it’s above that, there’s room for improvement, and anything over 500 milliseconds is considered poor.
For content-heavy pages like blog posts or news articles, INP might not be a major concern. Most interactions here are limited to scrolling or zooming in and out, which don’t impact INP.
However, if your page includes interactive elements like menus or sign-up buttons, they need to respond quickly. This is especially important for pages where users need to take fast action, like adding a product to their cart or logging in—on these types of pages, INP is crucial.
For example, think about the loading experience for a page like this:
With a login page like that, the time it takes for the content to load isn’t all that important (there isn’t all that much to load anyway).
What truly matters is how quickly you can start typing your login details and how fast the “Sign In” button responds.
To improve your INP score, here are some steps to consider:
- Minimize (or defer) JavaScript: Users can’t interact with your page while JavaScript is still loading. So, minimizing or deferring the loading of JS is essential for better responsiveness.
- Remove unnecessary third-party scripts: Similar to LCP, non-essential third-party scripts like Google Analytics or heatmaps can slow down INP. If your INP time is high, consider removing these extras.
- Defer code execution: Break up lengthy tasks into smaller chunks so the browser can process them more efficiently. You might need your developer’s help with this, but it’s worth the effort for faster interaction times.
Cumulative Layout Shift (CLS)
Cumulative Layout Shift (CLS) measures how stable your page is as it loads.
Simply put, if elements on your page shift or move around while it’s loading, that means you have a high CLS score, and that’s not good for user experience.
Ideally, you want your page elements to stay stable as the page loads.
Why?
Picture this: A user visits your store page and sees a button to learn more about a product. As they move to click the button, a banner pops up at the top, pushing everything down. Suddenly, they accidentally click the “Buy Now” button instead.
That’s a frustrating experience.
To avoid this, Google has set specific guidelines for what constitutes a good CLS score:
For a great user experience, aim for a CLS score of 0.1 or lower. If your score falls between 0.1 and 0.25, there’s room for improvement. Anything above 0.25 is considered poor.
This is an area I definitely need to focus on, especially for mobile users.
Here are some easy ways to reduce CLS:
- Set size attributes for images and videos: This helps the browser know exactly how much space each element will take up, preventing any layout shifts as the page loads.
- Reserve space for ads: Make sure your ads have designated space on the page to avoid them popping up unexpectedly and pushing content around.
- Avoid adding content above the fold: Inserting new elements, like banners, at the top of the page can push everything down when they load. Try placing these elements lower on the page instead.
Want to Dive Deeper into Core Web Vitals?
User Behavior and SEO: Discover how users interact with your website and how this affects your SEO strategy. Gain a better understanding of how your site’s structure, page speed, and user experience work together to impact your rankings.
Complete Guide to Page Speed and SEO: Learn how your site’s loading speed influences SEO and discover ways to improve it. Enhance your user experience and boost your chances of ranking higher on search engines.
Semrush Site Audit: Identify any issues with your site’s Core Web Vitals and get helpful tips on improving your scores. You can audit up to 100 URLs with a free account or start a 14-day free trial of Semrush Pro for even more insights.
Final Thoughts: Mastering Core Web Vitals for SEO and User Experience
Core Web Vitals—LCP, INP, and CLS—are key to enhancing both your site’s SEO and user experience. By focusing on speed, interactivity, and visual stability, you can improve rankings and keep visitors happy.
Optimizing your site’s load times, ensuring quick responses to interactions, and preventing unexpected layout shifts will create a seamless experience that both Google and users love. Regularly monitor your site’s performance with tools like Google Search Console or Semrush Site Audit to stay ahead.
Prioritizing Core Web Vitals will not only boost your SEO but also help build a site that users trust and enjoy visiting.