What is my screen resolution

The screen size and window size this browser reports, in CSS pixels, and what device pixel ratio does and does not measure.

How to read this

The first number is the screen size this browser reports, in CSS pixels. The window can be smaller. At a device pixel ratio of 2, 1920×1080 CSS pixels are about 3840×2160 device pixels. Zoom and OS scaling change the ratio, so that product is an estimate, not a measurement of the panel.

What leaves this tab

The sizes are read in this tab. They are not uploaded.

Related

My device What is my IP address What browser am I using What is my user agent What language is my browser What is my time zone Is dark mode on Resize an image Aspect ratio

FAQ

What is the difference between the screen and the window?

The screen is the display size the browser reports. The window is this page's viewport and can be smaller.

What does the device pixel ratio mean?

CSS pixels times the ratio are an estimate of device pixels. At a ratio of 2, 1920×1080 is about 3840×2160. Zoom and OS scaling change the ratio, so this is not a measurement of the panel.

Is this size an HTTP header?

No. The page reads it in the tab. It is not sent with the request unless some other script reads it and sends it.

Why can this differ from the monitor's advertised size?

OS scaling can make a 4K panel report a smaller CSS size. The browser reports the scaled size.

What about orientation?

Turning a phone swaps the width and height the browser reports. Refresh the reading by loading the page again after you rotate.