Browser Dev Tools Layout Features

Essential browser debugging tools for diagnosing CSS layout issues beyond basic element inspection.

Chrome/Edge DevTools:

• Layout Panel: Shows flexbox/grid overlays with numbered lines
• Computed Panel: Final calculated values, not authored CSS
• 3D View: Visualizes stacking contexts and z-index layers
• Coverage: Shows unused CSS for performance debugging

Firefox DevTools:

• Grid Inspector: Best-in-class CSS Grid debugging
• Flexbox Inspector: Visualizes flex containers and items
• Fonts Panel: Typography debugging and web font analysis
• Changes Panel: Tracks all CSS modifications in session

Key Debugging Features:

• Box Model Diagram: Interactive margin/padding/border visualization
• Hover States: See pseudo-class styles (:hover, :focus)
• Device Simulation: Test responsive layouts
• Console CSS: Live CSS property testing via $0.style.property = 'value'

Pro Tips:

• Right-click element → “Scroll into view” for finding hidden elements
• Use “Select an element” tool for precise element targeting
• Command Palette (Cmd+Shift+P) for quick feature access

Related: CSS Layout Debugging Strategy, CSS Responsive Debugging