What Is My Screen Resolution
See your screen resolution and viewport size.
Free · No sign-up · Works in your browser
About the What Is My Screen Resolution
Check your screen resolution instantly — this page detects and displays your display resolution in CSS pixels, your browser viewport size (which updates live as you resize the window), your device pixel ratio, and color depth. Handy for web developers testing breakpoints, support calls that ask “what resolution are you running?”, and checking what a Retina or 4K display really reports to websites.
How to use the What Is My Screen Resolution
- 1Open the page — your resolution is detected automatically.
- 2Resize the window to watch the viewport values update.
- 3Note the pixel ratio for native panel resolution.
Frequently asked questions
Why does my 4K monitor show 1920×1080?
Your OS is scaling the display (usually 200%) — sites see CSS pixels. Multiply by the device pixel ratio shown to get the native panel resolution.
What's the difference between screen and viewport?
Screen is your whole display; viewport is just the browser window's content area — what responsive design actually responds to.
What's the most common screen resolution?
1920×1080 leads on desktop worldwide, while 390×844-class sizes dominate mobile viewports.