JavaScript & CSS

Resource hints like preload, prefetch, and preconnect tell the browser to start loading critical files earlier. Learn when preloading helps and when it makes things worse.

Many WordPress pages load JavaScript and CSS that they never use. Learn what unused code is, how it accumulates from plugins and themes, and how it affects load time.

jQuery ships with WordPress core and many plugins depend on it. Learn why jQuery persists in WordPress, how it affects performance, and when it can be safely removed.

Third-party CSS and JavaScript that blocks rendering adds latency you cannot optimize away. Learn how external render-blocking resources affect LCP and what your options are.

Analytics, chat widgets, social embeds, and marketing tags all load third-party JavaScript that you do not control. Learn how external scripts affect your Core Web Vitals.

Every CSS file your page loads blocks rendering. Learn why WordPress sites accumulate too many stylesheets and how they affect your Largest Contentful Paint.

CSS blocks rendering until it fully loads. Critical CSS inlines the styles needed for above-the-fold content so the page can start rendering sooner. Learn how CSS delivery affects LCP.

Even after JavaScript downloads, the browser must parse and execute it — and that takes time, especially on mobile devices. Learn how execution time affects INP and overall responsiveness.

WordPress sites often load 20 or more JavaScript files on every page. Learn why JavaScript accumulates, how it affects performance, and how to identify the biggest contributors.

The defer and async attributes control when browsers execute JavaScript files. Learn the difference between them and why deferring scripts can dramatically improve LCP.

Render-blocking JavaScript prevents the browser from displaying your page until the script finishes loading and executing. Learn what makes a script render-blocking and how it affects LCP.