What Is My Screen Size?
Instantly discover your screen resolution, viewport dimensions, and detailed display information.
Understanding Screen Size & Resolution
Screen size and resolution are fundamental aspects of your display that affect everything from image clarity to how much content fits on screen. Understanding these specs helps you optimize your workspace and choose the right settings.
Key Display Concepts
- Screen Resolution: The total number of pixels your display can show, expressed as width × height (e.g., 1920 × 1080). Higher resolution means more pixels and sharper images.
- Viewport Size: The visible area of your browser window where web content is displayed. This is smaller than your screen resolution due to browser chrome, toolbars, and the taskbar.
- Device Pixel Ratio (DPR): The ratio between physical and CSS pixels. A DPR of 2× (common on Retina displays) means 4 physical pixels for every CSS pixel, producing sharper text and images.
- Aspect Ratio: The proportional relationship between width and height. Common ratios include 16:9 (widescreen), 16:10 (productivity), and 21:9 (ultrawide).
- Color Depth: The number of bits used to represent each pixel's color. 24-bit (8 bits per channel) provides 16.7 million colors. 30-bit adds HDR capability.
Common Screen Resolutions
- 1366 × 768 (HD): Budget laptops and older monitors
- 1920 × 1080 (Full HD): The most common desktop and laptop resolution
- 2560 × 1440 (QHD): Gaming monitors and high-end laptops
- 3840 × 2160 (4K UHD): High-end displays and professional work
- 5120 × 2880 (5K): Professional creative displays
- 3440 × 1440 (UWQHD): Ultrawide productivity and gaming
Frequently Asked Questions
Why is my viewport smaller than my screen resolution?
Your viewport is the visible area inside the browser window. The difference comes from browser UI elements (address bar, tabs, bookmarks bar), the OS taskbar, and any developer tools that may be open.
What does Device Pixel Ratio mean?
DPR tells you how many physical pixels correspond to one CSS pixel. A DPR of 2× (like Apple Retina) means each CSS pixel is rendered using a 2×2 grid of physical pixels, resulting in sharper text and images.
Why does my 4K monitor show 1920×1080?
Your OS may be using display scaling (e.g., 200%). The reported CSS resolution is 1920×1080, but with DPR of 2×, the actual physical pixels are 3840×2160. Check the "Physical Pixels" value above for your true resolution.
Does this work on mobile?
Yes! All values are detected from your device's browser. On mobile, you'll see your device's logical resolution and DPR, which is often 2× or 3× on modern phones.