Delimiter.live
Network & Web Tools Runs in your browser Free · no account

Screen Resolution Checker

This tool reports your screen resolution, the usable browser viewport, the device pixel ratio and the orientation, and tells you which common responsive breakpoint your window currently falls into. Values update live as you resize.

Display

Set your options and press the generate button.

Results update automatically and are calculated on your device. Nothing you type is sent to a server.

Runs in your browser. Processing happens entirely in your browser. Nothing you enter is sent to Delimiter.live.

How to use the Screen Resolution Checker

  1. Open the page — the values appear immediately and update as you resize the window.
  2. Compare the screen resolution with the viewport size to see how much space the browser interface takes.
  3. Check the pixel ratio to understand how CSS pixels map to physical pixels on your display.

Example

Input
Open the page
Output
Screen: 2560 × 1440
Viewport: 1280 × 720
Pixel ratio: 2
Breakpoint: lg

Common use cases

  • Confirming the resolution to report in a support ticket.
  • Checking which responsive breakpoint a layout problem occurs at.
  • Understanding why an image looks soft on a high-density display.
  • Verifying the viewport size while testing a responsive design.

Limitations and things to watch for

  • Screen resolution is reported in CSS pixels, not physical pixels. Multiply by the device pixel ratio to get the physical resolution — a 2× display reporting 1440 × 900 has 2880 × 1800 physical pixels.
  • On a multi-monitor setup the values describe the display the browser window is currently on.
  • Browser zoom changes the reported viewport size, because zooming changes how many CSS pixels fit on screen.

Frequently asked questions

Why is my resolution lower than my monitor specification?
Because it is reported in CSS pixels. On a high-density display each CSS pixel covers several physical pixels — multiply the reported size by the device pixel ratio to get the hardware resolution.
What is the difference between screen size and viewport size?
Screen size is the whole display. Viewport size is the area inside the browser window where the page is drawn, excluding the toolbar, tabs, scrollbars and any operating-system chrome.
What is device pixel ratio?
How many physical pixels represent one CSS pixel. Standard displays are 1, most modern laptops and phones are 2 or 3. It is why images need to be supplied at higher resolution to look sharp.

Share this tool