Screen Resolution Checker

See your live screen resolution, available area, browser viewport size, pixel ratio, aspect ratio, orientation, and breakpoint — and watch them update instantly as you resize the window.

Screen resolution

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Available area

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Viewport size

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Resize your browser window or rotate your device and every value updates live. Everything is read locally — nothing is sent anywhere.

ToolsSoup's Screen Resolution Checker is a live readout of your display and browser dimensions. It shows your full screen resolution next to the available area and your current browser viewport size, side by side, then breaks down the device pixel ratio, the true physical resolution in device pixels, the aspect ratio, the orientation, and which responsive breakpoint your viewport falls in. Every number updates instantly when you resize the window or rotate your device, and it all runs locally in your browser.

What is the Screen Resolution Checker?

It is a live display checker that reads your screen and viewport dimensions from the browser's screen and window APIs and shows them as they change. Screen resolution is the full size of your monitor in CSS pixels; the available area is the screen minus system bars like the taskbar or dock; the viewport size is the visible area inside your browser window. It also derives the device pixel ratio, the physical resolution (CSS pixels multiplied by the pixel ratio), the simplified aspect ratio, the orientation, and the breakpoint category for your current viewport width.

How to check your screen resolution

There is nothing to type — the values appear automatically and stay live:

  1. Open the tool and your screen resolution, available area, and viewport size load instantly in the three top cards.
  2. Read the detail rows below for pixel ratio, physical resolution, aspect ratio, orientation, and breakpoint.
  3. Resize the browser window or rotate your device and watch every value update in real time, then use Copy all to copy the full report.

Screen resolution vs viewport size

Screen resolution is the size of your whole display, the same value for every site you visit. Viewport size is only the area your web page can actually use — it shrinks when the window is not maximized, when developer tools are docked, or when browser chrome and scrollbars take space. Designers test against the viewport because that is what their responsive layout reacts to, while the screen resolution stays fixed regardless of window size.

Why use this screen resolution checker?

  • Shows screen resolution, available area, and browser viewport size side by side so the difference is obvious.
  • Updates live as you resize the window or rotate your device — no refresh or button needed.
  • Calculates the true physical resolution from CSS pixels and the device pixel ratio for high-DPI and Retina screens.
  • Reports the simplified aspect ratio, the portrait/landscape orientation, and the mobile/tablet/desktop breakpoint your viewport falls in.
  • Runs entirely in your browser — nothing is uploaded, logged, or stored.

Frequently asked questions

What is the difference between screen resolution and viewport size?

Screen resolution is the full pixel size of your monitor and never changes as you browse. Viewport size is the area inside the browser window your page can render into; it gets smaller when the window is not maximized or when docked developer tools, scrollbars, and toolbars take up space. Responsive layouts react to the viewport, not the screen.

Why is my physical resolution larger than the reported screen resolution?

On high-DPI and Retina displays the browser reports CSS pixels, not physical device pixels. The tool multiplies the CSS resolution by your device pixel ratio to estimate the physical resolution, so a 1512 × 982 CSS screen at a pixel ratio of 2 is roughly 3024 × 1964 physical pixels.

Do the values change when I resize the browser?

Yes. The viewport size, aspect ratio, orientation, and breakpoint are tied to your browser window, so they update live every time you resize it or rotate your device. Screen resolution and available area reflect the whole display and only change if you switch monitors or change your system display settings.

How is this different from the Browser Information tool?

Browser Information lists many static environment details — user agent, OS, time zone, and so on — including a single screen and viewport row. This tool focuses only on display dimensions, shows them prominently side by side, derives the aspect ratio, orientation, physical resolution, and breakpoint, and keeps every value live as you resize.