Core Web Vitals: A Quick Dive into Website Performance

by | May 24, 2024

Imagine your website is a busy café. Core Web Vitals (CWVs) are one of the secret ingredients that ensure your café runs smoothly, keeps customers happy, and gets rave reviews. They’re a set of performance metrics introduced by Google to measure the user experience of a website. These metrics focus on three key aspects: loading performance, interactivity, and visual stability.

Core Web Vitals Metrics

Let’s break down each of the metrics:

Largest Contentful Paint (LCP): This measures loading performance. Specifically, LCP is the time it takes for the largest piece of content (e.g., a large image or block of text) to appear on the screen. A good LCP score ensures users see something useful quickly.

First Input Delay (FID): This measures interactivity. FID is the time it takes for a page to respond after a user first interacts with it (e.g., clicking a button). A low FID score means your site feels responsive and quick.

Cumulative Layout Shift (CLS): This measures visual stability. CLS illustrates how much the content on the page shifts unexpectedly during loading. A low CLS score means users won’t experience annoying jumps as they try to read or click.

Why Are Core Web Vitals Important?

Think of Core Web Vitals as your website’s health check-up. Google considers these metrics when ranking pages in search results. A site that performs well on these metrics is likely to rank higher, leading to more traffic and happier users.

The Metrics in Action

Let’s visualize these metrics with an output from PageSpeed Insights:

Core Web Vitals from Google PageSpeed Insights

Here, we have multiple graphs representing page speed metrics, but let’s concentrate on the main three: LCP, FID, and CLS. Each bar shows an example score, with lower scores indicating better performance. The target scores are:

  • LCP: Less than 2.5 seconds
  • FID: Less than 100 milliseconds
  • CLS: Less than 0.1

How to Improve Core Web Vitals

Optimize LCP

Lazy Loading: Load images only when they are about to enter the viewport. Using plugins like Perfmatters helps accomplish this seamlessly.

Compression: Compress images and text files to reduce their size. TinyPNG offers effective and free drag-and-drop compression tools right on their website.

Server Response Time: Improve server response time using a faster server or a Content Delivery Network (CDN). We use a dedicated cloud VPS (virtual private server) through SiteGround to ensure website hosting is not an issue.

Reduce FID

JavaScript Optimization: Minimize the impact of third-party code and optimize JavaScript execution. Loading JavaScript at the end of the page can dramatically help page content load faster.

Browser Caching: Ensure that your website’s static assets, including images and custom font styles, are cached by the browser.

Minimize CLS

Preload Custom Fonts: Preload all custom fonts to prevent the browser from loading a built-in, already-supported font first. This is one of the top culprits of CLS issues, as supported fonts are loaded first, followed by the custom font, shifting your page layout to accommodate the custom font placement.

Set Size Attributes: Set size attributes (width and height) for images and videos to help the browser determine how much space to allocate on the page before the images load.

Tools to Measure Core Web Vitals

Google PageSpeed Insights: Enter your URL and get a detailed report on your site’s performance, including Core Web Vitals. These metrics are collected over a 28-day period, so don’t sweat it if you’ve made changes to your site and the numbers are still showing the same.

Web Vitals Extension: A Chrome extension that gives real-time feedback on Core Web Vitals as you browse.

Google Search Console: Google’s Search Console provides reports specifically for Core Web Vitals, showing how your pages are performing over time.

Wrapping Up

Core Web Vitals are essential for delivering a delightful user experience. By optimizing your website for LCP, FID, and CLS, you’re enhancing your site’s performance and boosting its ability to rank higher in search engines.

We know it can be a daunting task to manage these types of changes yourself. If you need a new website or are looking for someone to help make updates to your existing one, reach out, and we’ll help!