Guide · 6 min read
What Is My Screen Size? The Complete Guide to Screen Resolution
If you've ever asked yourself "what is my screen size?", you're in the right place. This guide explains screen resolution, viewport, and pixel density — and shows you how to find yours in one click.
The fastest way to check your screen size
The quickest way to find out is to use a free detector tool. Our what is my screen size checker reads your display dimensions the moment you visit the homepage — no clicks, no installs, no sign-up required. It shows your screen resolution, browser viewport, device pixel ratio, color depth, and operating system instantly.
What does "screen size" actually mean?
The phrase "screen size" can mean three different things, and it's important to know which one you need:
- Physical size — the diagonal measurement of your display in inches (for example, a 27" monitor).
- Screen resolution — the total number of pixels your display can show, written as width × height (for example, 1920×1080).
- Viewport size — the area inside your browser window where web pages are rendered. This is almost always smaller than your screen resolution.
Common screen resolutions in 2026
Most modern devices fall into a handful of standard resolution categories. Here are the ones you're most likely to see:
| Name | Resolution | Typical use |
|---|---|---|
| HD | 1280 × 720 | Older laptops, budget displays |
| Full HD | 1920 × 1080 | Most laptops & desktops |
| 2K / QHD | 2560 × 1440 | Gaming monitors, premium laptops |
| 4K UHD | 3840 × 2160 | High-end monitors, modern TVs |
Why does device pixel ratio matter?
Modern phones, laptops, and Retina displays pack more physical pixels into the same space. The device pixel ratio (DPR) tells you how many physical pixels make up one CSS pixel. A DPR of 2 means a "1920×1080" looking layout is actually rendered at 3840×2160 physical pixels — which is why text and images look so crisp.
When you'd want to know your screen size
- Designing or testing a website at the right breakpoints
- Buying a new monitor or laptop and comparing displays
- Setting up a video call, screen share, or live stream
- Choosing wallpapers and assets at the right resolution
- Filing a bug report that depends on viewport behavior
Frequently asked questions
Is screen resolution the same as screen size?
No. Screen size is the physical diagonal measurement, while resolution is the pixel count. Two monitors can be the same physical size but have very different resolutions.
Why is my browser viewport smaller than my screen?
Your operating system's taskbar, the browser's tabs and address bar, scrollbars, and any open dev tools all reduce the area available for the page. That's why the viewport is always smaller than your screen resolution.
How do I check my screen size right now?
The easiest way is to open our what is my screen size page — your full screen and viewport details appear automatically.
Ready to check your screen?
See your exact resolution, viewport, and pixel ratio in one click.
Detect my screen size