Scripts
Classic scripts without async or defer can pause HTML parsing. Modules defer by default. Preserve execution order and test page behavior before changing attributes.
Page resources · source loading evidence
Find blocking scripts, stylesheets, image attributes, and third-party resources
Download one public HTML document and inventory the resource declarations its source contains. Review parser-blocking JavaScript, render-blocking CSS candidates, loading hints, image dimensions and alternative text, cross-origin requests, and legacy nomodule delivery without a synthetic grade.
DOCUMENT2 MIB MAXROWS500 RETAINEDRENDERINGNOT EXECUTED
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Ready for a public HTML page.
No example resources, invented performance score, or generated findings are shown before a live bounded request.
Interpret before changing delivery
Connect source declarations to measured browser behavior
Stylesheets
Stylesheets that apply to the current media can delay rendering. Critical CSS and preload strategies have tradeoffs; confirm the actual request chain in browser tooling.
Images
Width and height attributes help browsers reserve space. Loading, fetchpriority, srcset, sizes, format, and placement should be evaluated together—especially for the likely LCP image.