Free Screen Resolution Test - Live Detect Resolution, DPR, Color Depth

Screen Resolution Test

Reads every display property the browser exposes — screen width/height, viewport, device pixel ratio, color depth, color gamut, orientation, and more — and updates live as you resize the window.

All values update live. Resize the window or zoom to watch the viewport and DPR change.

Native pixel resolution

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Screen resolution

Viewport (this tab)

Device pixel ratio

Color depth

Color gamut

Orientation

Screen aspect ratio

Available screen

Tip: DPR (device pixel ratio) multiplies CSS pixels to physical pixels. A Retina / 4K phone usually has DPR 2-3. Native resolution = screen × DPR. Browser zoom also changes DPR in modern browsers.

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Screen Resolution Test guide

How to use the Screen Resolution Test accurately

Modern browsers expose every relevant display property through the screen object and the window.devicePixelRatio property.

01 What This Tool Actually Reads Modern browsers expose every relevant display property through the screen object and the window.devicePixelRatio property.

02 CSS Pixels vs Physical Pixels The big source of confusion: when your phone says "1080 × 2400" physical, the browser reports something smaller like "390 × 844" for screen.width / height.

03 Color Gamut Detection The color-gamut CSS media query exposes which color gamut the OS and browser advertise. sRGB is the baseline — every display. DCI-P3 is wide-gamut, covering most modern phones, MacBooks, and premium monitors. Rec.

04 Why The Numbers Might Disagree With Specs Windows DPI scaling (125%, 150%, 175%) reduces the reported CSS resolution — a 4K display at 150% scale reports as 2560 × 1440. macOS HiDPI similarly reports half-size logical resolutions.

screen resolution test what is my resolution device pixel ratio dpr test color depth test viewport size checker

The color-gamut CSS media query exposes which color gamut the OS and browser advertise. sRGB is the baseline — every display. DCI-P3 is wide-gamut, covering most modern phones, MacBooks, and premium monitors. Rec.

Screen Resolution Test FAQ

Common screen resolution test questions

What is my screen resolution?

The tool shows both your CSS screen resolution and your native physical resolution (CSS × device pixel ratio). Most browsers report CSS pixels by default for text rendering consistency.

What is device pixel ratio?

Device pixel ratio (DPR) is how many physical pixels the browser uses to render one CSS pixel. DPR 1 is standard, 2 is Retina / HiDPI, 3 is common on high-end phones.

Why does my 4K monitor show 2560x1440?

Because Windows display scaling (125% or 150%) reduces the reported CSS resolution. The tool also shows native resolution, which multiplies the CSS value by DPR to reveal the true pixel count.

What is the color gamut of my display?

The tool queries CSS media queries for color-gamut support and reports sRGB, DCI-P3, or Rec. 2020. Most laptops and phones since 2020 support DCI-P3.

Checklist

Display checks to confirm

What This Tool Actually Reads Modern browsers expose every relevant display property through the screen object and the window.devicePixelRatio property.
CSS Pixels vs Physical Pixels The big source of confusion: when your phone says "1080 × 2400" physical, the browser reports something smaller like "390 × 844" for screen.width / height.
Color Gamut Detection The color-gamut CSS media query exposes which color gamut the OS and browser advertise. sRGB is the baseline — every display.