Output
CSS dimensions; pixel ratio; capability signals
UserBenchmark / All Tools / Screen Resolution Test
Display
Screen Resolution Test
Inspect screen size, viewport, pixel ratio and color capabilities.
Free to useNo downloadNo sign-up
Screen Resolution Test · At a glance
Quick answer: Inspect screen size, viewport, pixel ratio and color capabilities. Viewport dimensions describe the page area; screen dimensions and pixel ratio describe separate browser signals.
Screen Resolution Test
The test loads when you open it. Device access is requested only after you choose to start.
Detailed guide
How to use this tool
- Open the tool and compare screen dimensions, viewport size and device-pixel ratio.
- Resize the window to see which values change.
Input
Browser screen and viewport properties
Browser requirement
Screen API; devicePixelRatio; media queries
Processing
Runs on your device; no tool-result upload
How it works and what the result means
The result is a mathematical estimate under the stated formula. It does not read your hardware or change system settings.
Reading the result
Viewport dimensions describe the page area; screen dimensions and pixel ratio describe separate browser signals. Scaling can prevent a simple one-to-one physical-pixel reading.
What to check next
Reset zoom if viewport values are unexpected. Multiple monitors and operating-system scaling can change the reported signals.
Keep consistent units and compare the assumptions with your actual game, display or network configuration.
Frequently asked questions
Why does a 4K display show fewer CSS pixels?
CSS pixels are layout units. A high-density display or scaled desktop can use multiple device pixels for one CSS pixel.
How do I start the Screen Resolution Test?
Enter your own values and press Calculate. Units are shown beside each field; invalid or impossible values are rejected.
Does this tool require a download or an account?
No. Open the interactive tool above in a modern browser. The instructions and explanations are available even with JavaScript disabled; running a test needs JavaScript.
Why can two attempts give different results?
Power settings, background tasks, browser scheduling, operating-system input processing and device settings affect measurements. Compare repeated attempts with identical settings rather than the single highest score.