SEO AnalysisFree Tool
Render Blocking Resources
Identify JavaScript and CSS files in your page head that delay the First Contentful Paint (FCP).
Analyze Resources
What Blocks Rendering?
When a browser loads your page, it pauses everything to download and process certain files found in the <head>. These "render-blocking" resources delay what the user sees on screen.
- Synchronous JavaScript: Scripts without
asyncordeferblock the HTML parser completely. - External CSS: All CSS files in the head are render-blocking by default — the browser waits for them before painting.
How to Fix It
Eliminating render-blocking resources is one of the highest-impact optimizations you can make for Core Web Vitals.
Deferring non-critical JavaScript and inlining above-the-fold CSS can improve First Contentful Paint (FCP) by 30-50% on average.
Async & Defer Scripts
Add async or defer attributes to script tags so they load in the background without blocking rendering.
Inline Critical CSS
Put above-the-fold CSS directly in the HTML and load the rest asynchronously with media=
How to Use This Tool
Enter a URL and click "Analyze". We'll scan the page's <head> section for synchronous scripts and render-blocking stylesheets. Each blocking resource is listed with its type, URL, and specific explanation of why it blocks rendering.
Frequently Asked Questions
These are files (usually CSS and JavaScript) that prevent the browser from displaying your page content until they are fully downloaded and processed. This delays the
For JavaScript, use
Yes, significantly. Google uses
No. Inlining everything increases HTML document size. Only inline the CSS needed for
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