P1Issue #50
Eliminate render blocking resource
ā What does it mean?
ā What does it mean?
Render-blocking resources are CSS and JavaScript files that the browser must download, parse, and execute before it can render the visible part of the page (above-the-fold content).
If these resources are large or unnecessary for the first paint, they delay page rendering, increasing First Contentful Paint (FCP) and Largest Contentful Paint (LCP) times.
šØ Why is it important for SEO?
šØ Why is this a problem for SEO?
Slower Page Load ā Google favors sites that render quickly.
Poor Core Web Vitals ā Delays in FCP, LCP, and INP hurt rankings.
High Bounce Rates ā Users leave if they see a blank screen for too long.
Mobile Performance Impact ā Render-blockers are worse on slow connections.
ā How to Fix It
ā
Best Practices to Fix
Defer JavaScript: Use defer or async attributes to prevent JS from blocking rendering.
Inline Critical CSS: Load only the CSS needed for above-the-fold content inline, defer the rest.
Code Splitting: Load page-specific JS/CSS instead of global bundles.
Minify & Compress: Reduce file sizes for faster loading.
Use Font Display Swap for web fonts to avoid blocking text rendering.
ā Bad Example
š Example
ā Bad (Render-blocking resources):
<head>
<link rel="stylesheet" href="/css/styles.css">
<script src="/js/app.js"></script>
</head>
<body>
<h1>Hello World</h1>
</body>
š The browser waits to load /css/styles.css and /js/app.js before showing Hello World, delaying FCP.
ā Good Example
ā
Good (Optimized resources):
<head>
<!-- Inline Critical CSS -->
<style>
body { font-family: Arial, sans-serif; }
h1 { color: #333; }
</style>
<!-- Load non-critical CSS later -->
<link rel="stylesheet" href="/css/styles.css" media="print" onload="this.media='all'">
<!-- Defer JS -->
<script src="/js/app.js" defer></script>
</head>
<body>
<h1>Hello World</h1>
</body>
š The browser renders text immediately while loading CSS & JS in the background.
ā” Result
ā” SEO Impact of Fixing
Improves Core Web Vitals (FCP, LCP, INP).
Enhances crawl efficiency since Googlebot prioritizes fast pages.
Better mobile performance, lowering bounce rates.
Higher search rankings as Google rewards speed & user experience.