WordPress is an open source CMS with a wide variety of free and subscription-based plugins that are available for Google PageSpeed optimization. Most of these are designed to provide solutions for common problems that are flagged by the PageSpeed report audit. One of the most common recommendations for WordPress sites is to “defer parsing of JavaScript.” This method delays the download of JS files until after the main content has rendered and becomes responsive, improving the FID score dramatically.
Browser caching of UI elements and compression of HTML/CSS files are other important tactics that minimize the total file size of downloads for a WP page. Establishing a cache validator requires WordPress administrators to add cache-control headers with last-modified and etag values so that the browser can determine if content has been modified since the last page load. Cache-control headers allow websites to declare the amount of time that content should remain in the cache before expiring. You may need to edit the .htaccess file for the cache settings to propagate across a WordPress site. Make sure to minify and defer the loading of non-critical CSS files, or inject the code inline for better load times. Automating these tactics across a WordPress site with back-end support will improve the FID score across all of the pages.
When the caching system for a WordPress site has been established, it can be further optimized for Google PageSpeed and Core Web Vitals by implementing the optimization techniques listed above. The most important tactic is the compression of HTML, CSS, JavaScript, and image files, which reduces the overall download size. JavaScript minification, lazy-loading of images, inline injection of CSS, and web server optimization will also boost the performance of WordPress websites. Remove unrequired plugins and third-party scripts that can lead to unexpected delays in page loads to improve FID scores. Browser caching speeds up the loading of GUI elements.