Screen Resolution Checker
See your screen resolution, viewport size, pixel ratio and colour depth at a glance.
How to use the Screen Resolution Checker
- Open the page — your display details load automatically.
- Read your resolution, viewport and pixel ratio.
- Resize the window to watch the viewport value update.
About the Screen Resolution Checker
The screen resolution checker reads your display details straight from the browser and lays them out in one place: your screen resolution, the available screen area (minus taskbars and docks), the browser’s viewport size, the device pixel ratio, the effective physical resolution, the colour depth, and the current orientation. Resize the window and the viewport figure updates live.
It answers “what is my screen resolution?” at a glance, which is handy when you are buying or selling a used monitor, filing a support ticket, or checking the viewport a website actually sees on your device before you design or debug a layout for it.
One thing worth understanding: the screen resolution shown is what the operating system reports to the browser in CSS pixels, which is not always the raw pixel grid of the panel. The device pixel ratio is the missing piece — it explains why a sharp “1920 by 1080” laptop can report a smaller CSS resolution, and the effective-resolution line multiplies the two back together to recover the physical pixel count. Everything is read locally in your browser. Pair it with the dead pixel test or the webcam test.
Frequently asked questions
What is my screen resolution?
The top row shows it. It is the resolution your operating system reports to the browser, measured in CSS pixels, which is what web pages are laid out against.
Why does it not match the resolution I bought, like 1920 by 1080?
Display scaling is the reason. On a high-density screen the browser reports fewer CSS pixels than the panel physically has. The device pixel ratio captures the difference, and the effective-resolution line multiplies it back to the physical pixel count.
What is the difference between screen resolution and viewport?
Screen resolution describes your whole display. The viewport is only the drawable area inside the browser window, which is smaller and changes as you resize the window or open toolbars.
What does device pixel ratio mean?
It is the number of physical pixels packed into each CSS pixel. A value above one, common on modern laptops and phones, means a high-density display that renders text and images more sharply.
Is any of this information collected?
No. The values are read from your browser and displayed locally. Nothing about your display is sent to a server or stored.