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Screen Resolution Checker

Check your screen resolution, device pixel ratio, and viewport size. Free online screen info tool. No signup, instant, 100% private browser results.

How it works

The Screen Resolution Checker displays your device's physical screen resolution, logical resolution, device pixel ratio, viewport size, orientation, and color depth — the complete set of display metrics that affect how your website renders on this device.

Display metrics are essential for responsive web design and debugging layout issues. A "1440p display" has a physical resolution of 2560×1440 but a device pixel ratio of 1.5–2, meaning CSS sees a logical resolution of ~1280×960. High-DPI (Retina) displays have a ratio of 2–3, meaning a 1px CSS border actually renders as 2–3 physical pixels.

Metrics explained: - Physical resolution: actual pixels on the screen hardware (e.g., 2560×1440) - Logical resolution: resolution CSS uses for layout (e.g., 1280×720 on a 2× DPI display) - Device pixel ratio (DPR): physical / logical (1 = standard, 2 = Retina, 3 = high-DPI mobile) - Viewport: visible area of the browser window (less than screen if browser UI is visible) - Color depth: bits per channel (most modern displays use 24-bit / 8 bits per channel)

Why it matters: a background image displayed at 800px wide on a Retina display needs to be 1600px to look sharp. CSS media queries use logical pixels, not physical pixels. A user with a 4K monitor but 200% scaling shows the same logical resolution as a 1080p monitor at 100% scaling.

Frequently Asked Questions

Why is my 4K monitor showing a lower resolution?
Windows and macOS scale 4K displays to a logical resolution for usability. A 3840×2160 monitor at 200% scaling presents as 1920×1080 in CSS and JavaScript. The 'logical resolution' is what affects layout; the 'physical resolution' is the actual screen pixel count.
What is device pixel ratio and how does it affect images?
Device pixel ratio (DPR) = physical pixels / CSS pixels. On a DPR 2 screen, a CSS image displayed at 400px wide uses 800 physical pixels. For sharp images on Retina displays, serve images at 2× or 3× the CSS display size.
Why do I see different values in CSS media queries vs. this tool?
CSS media queries use logical (CSS) pixels, which match the logical resolution shown here. window.screen.width also returns logical pixels. Physical resolution (before DPR scaling) is available via window.screen.width × devicePixelRatio.
What is the common screen resolution of website visitors?
As of 2024: 1920×1080 is the most common desktop resolution (~25% of users). 1366×768 is second (~15%). 1440×900 and 2560×1440 are common for higher-end displays. Mobile: 390×844 (iPhone 14), 414×896 (iPhone 11), 360×800 (common Android).