Screen Resolution Checker

Screen Resolution Checker displays physical screen dimensions, browser viewport size, device pixel ratio, and orientation as you resize the window—live updating for responsive CSS debugging.

Designers confirm breakpoint behavior matches real hardware instead of guessing from DevTools presets alone.

Client bug “sidebar breaks on my laptop” needs exact viewport width—this tool reports numbers without remote desktop.

Retina displays at DPR 2 confuse px vs CSS px discussions—explicit readout settles debates.

• Document viewport width in responsive bug tickets
• Verify media query breakpoints during CSS reviews
• Compare external monitor vs laptop built-in screen
• Test orientation change on tablets rotated in hand
• Confirm 4K scaling factor affecting layout density

1. 1Open the tool on the device or browser under test.
2. 2Read screen and viewport values in the dashboard.
3. 3Slowly resize browser window and watch live updates.
4. 4Rotate mobile device to compare portrait vs landscape readouts.
5. 5Copy or screenshot values for design system documentation.

• Viewport Size Checker focuses on inner width/height if you need minimal UI.
• Device Information adds touch and OS hints alongside resolution.
• Compare with CSS breakpoint variables in your codebase side by side.
• Zoom level not 100% skews CSS pixel readings—reset zoom before QA.

• Browser chrome and OS taskbars reduce viewport below screen resolution on maximized windows.
• Multi-monitor setups report the screen hosting the window—move window to test each display.
• Common mistake — quoting screen resolution when bug is viewport-specific: cite both values.