Screen Resolution Checker
Check your screen resolution, viewport size, aspect ratio and device pixel ratio instantly.
Your screen resolution
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Detecting…
- Screen resolution
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- Available screen area
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- Browser viewport
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- Browser window
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- Device pixel ratio
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- Physical pixels
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- Aspect ratio
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- Orientation
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- Color depth
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- Touch points
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Values update live — resize the window or rotate your device to watch them change.
How it works
This screen resolution checker reads your display information straight from the browser
the moment the page loads — no test to run and nothing to install. Screen resolution is
the full size of your monitor in CSS pixels, while the browser viewport is only the part
of the page you can actually see, so the two numbers differ whenever the window is not
maximised or the browser has tabs, toolbars and bookmarks bars. Multiplying the screen
size by the device pixel ratio gives the physical pixels your hardware really has, which
is why a Retina or 4K display reports a smaller CSS resolution than the number printed on
the box. Everything is read locally with plain JavaScript (window.screen,
window.innerWidth and devicePixelRatio); nothing about your
device is uploaded, logged or shared.
Frequently asked questions
What is my screen resolution?
The big number at the top of this page is your screen resolution: the full width and height of your display in CSS pixels, read directly from your browser. On a standard monitor that matches the resolution set in your operating system's display settings, for example 1920 × 1080 for a Full HD screen. The page names common resolutions for you and updates the moment anything changes.
What is the difference between screen resolution and browser viewport size?
Screen resolution is your whole display, while the browser viewport is only the area a web page can draw in. The viewport is always smaller because the browser's tabs, address bar, bookmarks bar and any window borders take up space, and it shrinks further when the window is not maximised. Web designers test responsive breakpoints against the viewport size, not the screen resolution.
Why does my screen resolution look smaller than my monitor's advertised resolution?
High-density displays such as Retina and 4K screens report a scaled CSS resolution so text stays readable. The device pixel ratio tells you the scaling factor — a ratio of 2 on a 1920 × 1080 CSS resolution means 3840 × 2160 real hardware pixels. This tool shows both: the CSS resolution your browser uses for layout and the physical pixel count your panel actually has.