Core Web Vitals are a set of metrics that measure the user experience of your website in terms of loading, interactivity, and visual stability. Google uses these metrics to evaluate the quality of your website and rank it in its search results. If you want to optimize your website for Google’s Core Web Vitals, you need to focus on three aspects: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS).
Largest Contentful Paint (LCP)
LCP measures how long it takes for the largest content element on your page to load, such as an image, a video, or a text block. A fast LCP indicates that your page is providing a good initial impression to the users and that they can access the main content quickly. A slow LCP, on the other hand, can frustrate the users and make them abandon your page.
According to Google, you should aim for an LCP of 2.5 seconds or less. To achieve this, you need to optimize your images, use a CDN, cache your assets, and minimize your CSS and JavaScript.
Optimize your images
Images are often the largest content elements on a page and can significantly affect your LCP. To optimize your images, you should:
- Compress your images to reduce their file size without compromising their quality. You can use tools like TinyPNG, ImageOptim, or ShortPixel to compress your images.
- Resize your images to fit the dimensions of their containers. You can use tools like ResizeImage.net, PicResize, or IrfanView to resize your images.
- Use the correct image format for different purposes. For example, use JPEG for photos, PNG for graphics with transparency, and WebP for both photos and graphics with better compression.
- Use responsive images to serve different image sizes based on the device width and pixel density. You can use the
<picture>
element or thesrcset
andsizes
attributes to implement responsive images. - Use lazy loading to defer loading images that are not in the viewport until they are needed. You can use the
loading="lazy"
attribute or a plugin like Lazy Load by WP Rocket to enable lazy loading.
Use a CDN
A CDN (Content Delivery Network) is a network of servers that deliver your content from the nearest location to the user. This reduces the latency and improves the loading speed of your content. A CDN can also provide other benefits such as caching, compression, security, and scalability.
To use a CDN, you need to sign up for a CDN service provider such as Cloudflare, Cloudinary, or KeyCDN and configure it with your website. You can also use plugins like WP Rocket or W3 Total Cache to integrate a CDN with your WordPress site.
Cache your assets
Caching is a technique that stores a copy of your assets (such as HTML, CSS, JavaScript, images, etc.) on the browser or the server so that they can be reused without fetching them again. This reduces the number of requests and improves the loading speed of your assets.
To cache your assets, you need to set the appropriate HTTP headers such as Cache-Control
, Expires
, and ETag
that instruct the browser or the server how long and how often to cache your assets. You can also use plugins like WP Rocket or W3 Total Cache to enable caching on your WordPress site.
Minimize your CSS and JavaScript
CSS and JavaScript are essential for styling and adding functionality to your website. However, they can also block the rendering of your page and delay your LCP if they are not optimized.
To minimize your CSS and JavaScript, you should:
- Remove any unused or unnecessary code from your CSS and JavaScript files. You can use tools like PurgeCSS or UnCSS to remove unused CSS and tools like UglifyJS or Terser to remove unused JavaScript.
- Combine multiple CSS and JavaScript files into one file to reduce the number of requests. You can use tools like Concat or Merge Fil.es to combine files online or plugins like Autoptimize or WP Rocket to combine files on WordPress.
- Minify your CSS and JavaScript files to remove any whitespace, comments, or redundant code that can increase their file size. You can use tools like CSS Minifier or JavaScript Minifier to minify files online or plugins like Autoptimize or WP Rocket to minify files on WordPress.