Screen Resolution Checker

Instantly detect your device's exact screen resolution, viewport size, and pixel ratio.

About Screen Resolution Checker

Are you a developer testing layouts? Use the Free Screen Resolution Checker. It's the Best Display Tester to accurately check monitor resolution online and view CSS pixel ratios.

Features

Detects your total hardware Screen Resolution (e.g., 1920x1080)
Detects your current Browser Viewport (the actual usable space)
Identifies Pixel Ratio (Retina/High-DPI displays)
Updates dynamically if you resize your browser window
No installation needed

How to Use

Simply open the tool page.
Your screen resolution will be displayed in massive numbers instantly.
Look below to see your browser viewport dimensions and pixel density.
Try resizing your browser window to see the viewport values change in real-time.

Frequently Asked Questions

What is the difference between Screen Resolution and Viewport?

Screen resolution is the total physical pixels on your monitor. Viewport is the area inside your web browser where websites actually render, which excludes the taskbar, scrollbars, and browser tabs.

Why does a 4K monitor show a lower resolution here?

Modern operating systems use "Display Scaling" (e.g., 150% scaling in Windows) so text isn't too tiny to read. This tool shows the CSS "logical" pixels, while the Pixel Ratio data confirms the high-density hardware.

What is a good viewport size for web design?

Designers usually target 1920x1080 for desktop, 768x1024 for tablets, and 360x800 for modern mobile phones.

Does this tool save my data?

No, all dimension checking is done instantly via local JavaScript APIs and is never transmitted.

Why does it show a smaller resolution than my monitor?

If you are on a high-DPI display (like Retina), it shows 'CSS Pixels'. Your physical pixels are multiplied by the device pixel ratio.

What is viewport size?

Viewport size is the exact pixel dimension of your browser window, excluding toolbars.

Is the data sent to a server?

No, this tool simply asks your browser to report its dimensions locally.

Is this a free screen resolution checker?

Yes, this free screen resolution checker is fully open.

Why use the best display tester?

It provides instant clarity for UI designers dealing with responsive web design.

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