UI Inspect
Browser Extension

Element Inspector

Inspect any element's box model, spacing, alignment, and computed styles with configurable visualization overlays.

The Element Inspector is the core feature of the browser extension. Hover over any element to see detailed visual overlays showing dimensions, spacing, alignment, and typography.

Inspector settings

All visualization features can be toggled independently:

SettingDescriptionDefault
Alignment GuidesFull-page crosshair lines from element edges (red dashed)On
Box ModelMargin/border/padding/content colored overlaysOn
Internal SpacingGap visualization between child elements (purple)On
Internal Alignment GuidesEdge lines across child elements (blue)Off
MeasurementsWidth/height dimension labelsOn
Info LabelElement tag, classes, typography, colors panelOn

Visualization layers

Box model

Shows the CSS box model with color-coded regions:

  • Content — Blue highlight
  • Padding — Green overlay
  • Border — Yellow overlay
  • Margin — Orange overlay

Each region shows its exact pixel values.

Alignment guides

Red dashed crosshair lines extend from all four edges of the hovered element to the viewport edges. Distance labels show the pixel distance from the element to the page edges.

Internal spacing

Purple indicators between direct child elements showing the gap in pixels. Useful for verifying consistent spacing in flex/grid layouts.

Internal alignment guides

Blue lines showing edge alignment across significant child elements. Helps verify that internal elements are properly aligned.

Advanced options

OptionDescription
Deep modeTraverse nested descendants up to 4 levels deep
Include text linesShow line-height based edges for text elements
Extend to viewportExtend alignment lines to full page (not just container)
Include small elementsInclude SVG icons and elements smaller than 20px

Info label

A floating panel showing:

  • Element tag name and CSS classes
  • Font family, size, weight, line height
  • Foreground and background colors (with contrast ratio)
  • Box model values (margin, padding, border)
  • Element dimensions

Significant element detection

The internal alignment feature filters elements to reduce noise:

Included: buttons, links, inputs, headings (h1-h6), paragraphs, images, containers with content

Excluded: SVG/icons, tiny elements (smaller than 20px), purely decorative elements

The algorithm uses a 3px edge tolerance to avoid duplicate lines and limits traversal to 4 levels even in deep mode.

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