Screen Resolution Detector
See your screen size, DPR and aspect ratio.
How to use
- 1 Open the tool — your display metrics appear immediately.
- 2 Resize the browser window to watch the viewport values change.
- 3 Check the aspect ratio and device pixel ratio for HiDPI displays.
- 4 Click Copy report to share the details.
About Screen Resolution Detector
The Screen Resolution Detector shows the exact dimensions of your display and browser in one quick glance.
It is the fastest way to answer questions like "what resolution am I running?", "what is my viewport size right now?" or "is this a Retina/HiDPI screen?" — useful for designers checking breakpoints, developers debugging responsive layouts, and anyone reporting a display issue.
The tool reads several values straight from the browser.
It reports the logical screen resolution and the true physical pixel count (screen size multiplied by the device pixel ratio), so HiDPI displays are obvious.
It shows the available area, which excludes operating-system chrome like the taskbar or dock, and the live browser viewport, which is the space your page actually has to work with.
It also reduces your screen dimensions to a simple aspect ratio such as 16:9 or 5:4, lists the device pixel ratio, and reports the colour depth in bits.
Resize your window and the viewport figures update in real time, which makes it easy to test responsive designs at specific widths.
Every value is read locally — nothing is sent to a server, nothing is stored — and you can copy the whole report to your clipboard with a single click to drop into a bug report or design note.
FAQ
Why is my physical resolution larger than the reported screen size?
Browsers report screen size in CSS pixels. On HiDPI/Retina displays each CSS pixel maps to several physical pixels, so we multiply by the device pixel ratio to show the true physical resolution.
Does the viewport really update as I resize?
Yes. The viewport figures listen for resize events and refresh live, which is handy for testing responsive breakpoints.