SCREENBLACK

FREE DISPLAY TOOL

Screen Resolution & Scaling Checker

See what your browser reports about the screen and viewport, then use simple patterns to spot visible scaling or softness.

BROWSER READOUT

Your current display information

Values update when the viewport or browser-reported display settings change.

Browser viewport—CSS pixels
Screen dimensions—Browser-reported CSS pixels
Device-pixel ratio—Browser-reported scale
Visual viewport scale—Where supported by your browser
Approximate effective pixel dimensions—Screen CSS size × device-pixel ratio; estimate only, not a verified panel resolution

Ready

VISUAL SCALING CHECK

1 CSS-pixel alternating lines

Pattern note: These patterns are drawn in CSS pixels. Softness, moiré or uneven lines can be caused by browser zoom, operating-system scaling, the graphics path or the display. They are clues—not a pass/fail hardware measurement.

HOW TO USE IT

Read the numbers as browser values, not a hardware certificate

The viewport is the page area available to the browser, measured in CSS pixels. Screen dimensions are the values the browser reports for the current display. Device-pixel ratio describes a relationship between CSS pixels and device pixels, but can be affected by operating-system scaling, browser zoom, display configuration and browser behavior.

For that reason, this page does not claim to reveal a guaranteed native physical panel resolution. The approximate pixel dimensions are only a calculation from browser-reported values. Use the display maker’s specifications or your operating system’s display settings to confirm the panel’s recommended or native resolution.

  1. Keep your usual display settings first. Note the browser zoom, operating-system scaling and whether HDR is enabled.
  2. Resize the browser window. The viewport reading should change while the screen dimensions generally remain tied to the display.
  3. Compare the visual patterns. Look for consistent lines and squares; if they appear soft, test at your normal browser zoom and then compare with the default zoom.
  4. Change one setting at a time. If you adjust zoom, resolution or scaling, repeat the same pattern before deciding what changed.
Important: A browser pattern cannot measure panel sharpness, physical pixel count, color accuracy, refresh rate or warranty eligibility.

WHAT TO TRY NEXT

Use the test that matches the issue

If a pattern looks unusual, compare it with a focused tool rather than relying on this page alone. Try the Gradient & Banding Test for tonal transitions, the Screen Uniformity Test for broad brightness or color differences, the Dead Pixel Test for fixed points across several colors, or the Refresh Rate Estimator for browser animation cadence.

On Windows, Microsoft recommends using the resolution marked “Recommended” as a starting point; the available options depend on the display and system. See Microsoft’s resolution and layout guide. Other operating systems have their own display settings and terminology.