What Is My Screen Size?
Your screen resolution is
Try resizing this window — all values update live
Every tool, by the job you're doing
Start from the problem you're chasing — each group opens the focused tool built for it.
Debug layout & breakpoints
Find which viewport, media query or breakpoint is active right now.
Debug sharpness & assets
Fix oversized screenshots and blurry exports with the right pixel math.
Compare real hardware
Physical dimensions, density and side-by-side device context.
About this screen size checker
Everything above reads directly from your browser and updates live as you resize — screen, window, viewport and scaling, packaged into one copyable report. Developers, designers and QA teams use it as the fastest broad readout when debugging responsive layouts across devices.
- Resolution
- The display's full pixel grid. Describes the hardware itself — not what your CSS actually sees.
- Viewport
- The area the page renders into. Media queries and breakpoints respond to this, not the full screen.
- Device pixel ratio
- Physical pixels packed into one CSS pixel. Drives sharpness and how large exported images should be.
- Physical size
- The real diagonal in inches. Sets true-size rendering and pixel density (PPI).
Anonymous aggregate stats are stored as monthly counts, not raw visit records.
Frequently asked questions
› What is my screen size?
Your screen size has two meanings: the physical size of your display measured diagonally in inches, and the screen environment your browser reports in pixels. This page gives the complete overview; for a resolution-only view, use the screen resolution checker.
› What is the difference between screen resolution and viewport size?
Screen resolution is the full pixel size of your display. The viewport is only the part of the browser window where the page renders, so CSS media queries respond to the viewport instead of the screen. For layout debugging, open the viewport size checker.
› Why does my screen show fewer pixels than advertised?
Modern displays use scaling. A laptop sold as 2560 × 1664 typically reports a smaller CSS-pixel value because the device pixel ratio (DPR) is 2. For image sharpness and asset sizing, use the device pixel ratio checker.
› Is any of this data sent to your servers?
The live detection runs in your browser. We count anonymous aggregate screen-environment buckets to power comparison stats, but we do not store raw visits, IP addresses, user IDs, full user-agent strings, copied reports or shared report links.