Free Online Screen Resolution Checker
Screen resolution refers to the total number of pixels your display can show horizontally and vertically. A 1920 × 1080 resolution, for example, means your screen holds over 2 million individual pixels. Knowing these dimensions is the first step to creating high-quality digital content. Once you know your resolution, you can boost your site's accessibility with our Color Contrast Checker to keep your design readable across all display types.
Whether you build websites, design interfaces, or game, knowing your screen resolution matters for a smooth experience. Developers use this data to build responsive layouts that look great on everything from phones to 4K monitors. If you design interactive elements for high-resolution screens, use our CSS Animation Generator to create smooth, pixel-perfect transitions that scale beautifully on any display. This tool keeps the workflow simple: read your stats on the left, supporting content below, and the sidebar on the left for popular and related tools.
Instant detection
Get your screen specs right away, with no need to dig into system settings.
Responsive testing
Resize your window to see exactly how breakpoints behave in real time.
Design accuracy
Optimize graphics and animations for the right pixel density every time.
Private by design
Everything runs in your browser, so your hardware data never leaves your device.
How it works
- Open the page and let the tool read your display details.
- Check your screen resolution, viewport size, and pixel ratio on the left.
- Resize the browser to watch the viewport update live.
- Read the result panel to learn what each metric means.
- Use the numbers to tune your responsive layouts and graphics.
Best practices
- Test your design at several common viewport widths.
- Account for device pixel ratio when exporting images.
- Use scalable units like rem and percentages for layouts.
- Check contrast so text stays readable at any resolution.
- Confirm breakpoints behave as you resize the window.
- Preview on both standard and HiDPI screens before launch.
Frequently asked questions
What is the difference between Screen Resolution and Viewport?
Screen resolution is the hardware's total pixel count, while the viewport is the actual area inside the browser window where the website is visible.
Can this tool detect external monitors?
Yes. It detects the resolution of whichever screen the browser window is currently displayed on.
Does it update when I resize the browser?
Yes. The viewport dimensions update in real time as you resize the window, which helps you test responsive designs.
How does resolution affect accessibility?
Higher resolutions can make text appear smaller. Use a Color Contrast Checker to confirm your text stays legible against its background for all users.
What is Device Pixel Ratio (DPR)?
DPR is the ratio between physical pixels and logical pixels. High-density screens like Retina have a higher DPR to make images look sharper.
Will animations look different on different resolutions?
They shouldn't, but performance can vary. You can use our CSS Animation Generator to create efficient code that performs well on any screen.
Is my screen data stored?
No. All calculations run client-side. Your hardware specifications are never recorded or shared.
Why does my resolution look lower than advertised?
This is often due to scaling settings in your OS, like Windows or macOS, that make text and icons larger and easier to read.
Can this tool detect 4K or 8K displays?
Yes. The tool reports high-definition resolutions as supported by your browser and hardware.
Does resolution affect battery life?
Generally yes. Higher resolutions need more processing power for graphics, which can lead to higher battery use on laptops and mobile devices.
Need more developer tools? Keep your design readable with the Color Contrast Checker tool, or build smooth transitions with the CSS Animation Generator tool.