Screen Resolution & Device Info
Detect your screen resolution, viewport size, DPI, device pixel ratio, breakpoint, browser and hardware info in real time.
What is Screen Resolution Tester?
Screen Resolution Tester is a browser diagnostic tool that instantly reports your current display and browser environment. It detects your physical screen resolution, the current viewport dimensions, device pixel ratio (DPI scaling), colour depth, touch support, device type classification (mobile, tablet, or desktop), and the browser and operating system you are running.
This information is invaluable when building or debugging responsive websites and web applications. A screen resolution of 1920 x 1080 tells you the physical pixel count of the display, but the viewport — the actual area available to your web content — is often different due to browser chrome, taskbars, and scrollbars. The device pixel ratio (DPR) tells you how many physical pixels correspond to one CSS pixel, which matters enormously for image sharpness. A DPR of 2 means a device is a high-density Retina display, and images served at 1x resolution will look blurry on it.
Developers use this tool during responsive design work to quickly verify what environment a test device is reporting without opening DevTools. QA testers share screen details when reporting bugs to give developers the exact context needed to reproduce an issue. Designers checking their work across devices can confirm the exact viewport dimensions and scaling factor affecting layout.
The tool also detects whether the device supports touch input, which affects hover-state design and click target sizing decisions — critical for accessibility and mobile usability.
How to Use Screen Resolution Tester
- Open the tool on your device
Visit the Screen Resolution Tester on the device you want to inspect. No settings or inputs are needed.
- Read your display details
Your screen resolution, viewport size, device pixel ratio, and colour depth are displayed immediately on page load.
- Check device and browser info
View your detected device type (mobile, tablet, or desktop), browser name and version, and operating system.
- Resize to test breakpoints
Drag your browser window to different sizes to see the viewport dimensions update live as you test responsive breakpoints.
Key Benefits
All display, browser, and device information appears immediately without any input, login, or extension required.
See the device pixel ratio so you know whether high-resolution images are needed for crisp display on the current screen.
Know at a glance whether the current device is being classified as mobile, tablet, or desktop by the browser.
Screen data is read locally from your browser APIs and never transmitted anywhere.
Frequently Asked Questions
Screen resolution is the total number of pixels on the physical display. Viewport size is the portion of that display available to web content, after subtracting the browser toolbar, scrollbars, and OS taskbar.
DPR is the ratio of physical pixels to CSS pixels. A DPR of 2 means 4 physical pixels correspond to each CSS pixel, as found on Retina and high-density displays.
Opening the browser DevTools panel reduces the space available to the page, which shrinks the viewport. Always test responsive layouts with DevTools closed or undocked.
The tool detects the browser's touch capability and displays a clear yes or no. This is based on the presence of touch event APIs, not the device type.