Screen Resolution Tester
Your screen resolution, browser viewport size, pixel ratio and color depth — all shown live, updating as you resize.
How to use — Screen Resolution Tester
- All your screen details appear as soon as the page loads.
- Resize the browser window — the viewport size updates live.
- Use "Copy details" to copy all the info and send it to support/a developer.
FAQ
What's the difference between screen resolution and viewport?
Screen resolution is the full display size (e.g. 1920×1080). The viewport is the area inside the browser window where the website shows — excluding the taskbar, address bar, etc. For web designers, the viewport is what matters.
What is pixel ratio (DPR)?
Device Pixel Ratio — how many physical pixels make up 1 CSS pixel. On Retina/high-DPI screens it's 2 or 3 — meaning a phone that looks like 1080p actually renders 2160+ pixels.
My phone says 4K but this shows less — why?
The browser shows CSS resolution (physical ÷ DPR). The "Effective resolution" row shows CSS × DPR — that's your true physical resolution.
What is this info useful for?
Website testing, planning screenshot sizes, giving system info to support, or verifying a monitor's claimed vs actual resolution.