Page DOM Stats

Gather statistics on DOM and CSS

This is a simple Chrome extension to inspect performance-related properties of a web page: - DOM size and structure: - Total number of nodes, split into elements and text nodes - Hidden nodes — inside `display: none` subtrees - Shadow DOM: number of roots and nodes in shadow trees - Iframes — same-origin ones are measured too; cross-origin ones are counted as unmeasurable - Top tags by frequency - Maximum and 95th-percentile number of children (fan-out) - Maximum and 95th-percentile depth - Maximum number of attributes per element and the number of inline `style` attributes - Number of scripts, including inline ones - CSS size: - Style sheets: total, inline, adopted, and unaccessible (cross-origin) - Rules and selectors: totals and per-sheet maxima - Performance: - Timings: time to first byte, `DOMContentLoaded`, load, first contentful paint, largest contentful paint, cumulative layout shift - Requests and transferred bytes, broken down by type - Number of loaded fonts and the JS heap size (Chrome) - Verdicts against Lighthouse guidance where a value crosses it: total nodes, children, depth