What is my screen resolution?
Your screen resolution as your browser reports it, plus device pixel ratio, viewport, color depth, aspect ratio, and orientation.
Screen resolution test workspace
How to use
4 short steps.
Read the big number
It is your screen resolution in CSS pixels, the size your browser lays pages out at.
Check the device pixel ratio
If it is above 1, your system is scaling. The estimated physical size under the big number multiplies the two together.
Compare with your display settings
Open the system display settings. The resolution there is the panel's native size; the number here is that size divided by the scale.
Enter your screen size for pixel density
Type the diagonal in inches to get an estimated pixels per inch.
What the result means
Match what you see to one of these.
If the number matches your display settings, there is no scaling
If the big number equals the resolution in your system settings, the device pixel ratio is 1 and each CSS pixel is one physical pixel.
If the number is smaller than expected, scaling is on
If a 4K display reads 1920 x 1080 with a device pixel ratio of 2, the panel is still 3840 x 2160. The system doubles everything so text is readable. That is normal on high density displays.
If the viewport is much smaller than the screen, the window is not maximized
If viewport and screen differ by a lot, the browser window is small or the sidebar, bookmarks, or split view take space.
Troubleshooting
If the test fails, try these in order.
Set browser zoom to 100%
Press Ctrl+0 or Cmd+0. Zoom changes the device pixel ratio and the viewport, so reset it and read the values again.
Move the window fully onto one monitor
With two displays of different density, the values follow the display that holds most of the window. Drag it over and the numbers update.
Check the scale setting
In Windows Display settings look at Scale; on macOS look at Resolution in Displays. Set 100% or Default to see the native size here.
What this test can't tell you
Where a browser check stops.
- Browsers report screen.width and screen.height in CSS pixels, so with scaling on they are smaller than the panel's native resolution; the physical estimate multiplies by devicePixelRatio and can be off by rounding.
- Physical size and pixel density cannot be read from the browser; they need the diagonal you type in or the display's specification.
FAQ
Common questions about this test.
What is my screen resolution?
The big number at the top of this page is your screen resolution in CSS pixels. If the device pixel ratio is above 1, the estimate under it shows the likely native resolution of the panel.
Why is the reported screen resolution lower than my monitor's?
Display scaling. Windows, macOS, and phones scale the interface so text is readable, and the browser reports the scaled size. Multiply by the device pixel ratio to get the native size.
What is device pixel ratio?
It is how many physical pixels the display uses for one CSS pixel. A ratio of 2 means a 4K panel behaves like a 1920 x 1080 layout with sharper text. Browser zoom changes it too.
Is 1920 x 1080 the same as 1080p or Full HD?
Yes. 1080p, Full HD, and 1920 x 1080 all describe the same 16:9 resolution. 2560 x 1440 is 1440p or QHD, and 3840 x 2160 is 4K UHD.