What does this tool do?
Screen Resolution Checker instantly shows your screen resolution, viewport size, pixel ratio, color depth, and orientation. You don't need to install anything to learn your device's real display properties. All values are read directly from the browser and update in real time.
How to use it
- Adjust the values and options.
- See the result in the live preview.
- Copy the generated CSS/code into your project.
How it works
The tool reads values from the browser's screen and window objects: screen.width/height gives the screen resolution, innerWidth/innerHeight the viewport, and devicePixelRatio (DPR) the ratio of physical to logical pixels. When you resize the window or rotate the device, the values update immediately, so you can observe responsive behavior live.
Common use cases
Developers testing responsive designs verify different viewport sizes, while users who want to add accurate display info to bug reports read these values quickly. The DPR figure helps plan correct asset sizes for Retina screens. It's also a handy reference when you can't remember your monitor's resolution.
Frequently asked questions
What's the difference between screen resolution and viewport size?
Screen resolution is the total pixel size of your monitor; the viewport is the inner area of the browser window where the web page is displayed. Because of toolbars and window borders, the viewport is usually smaller than the screen resolution.
What does the devicePixelRatio (DPR) value mean?
DPR is the number of physical pixels that correspond to one CSS pixel. On Retina screens this is typically 2 or 3, meaning an area defined as 1 pixel in CSS covers 2×2 or 3×3 physical pixels on screen.
Is Screen Resolution Checker free?
Yes. Screen Resolution Checker and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Screen Resolution Checker works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.