What Is My Screen Size?

What Is My Screen Size? is a free, browser-based tool that instantly detects your device's screen size, resolution, pixel density, and other display specifications without collecting or storing any data.

What is What Is My Screen Size?

It is a free online tool that automatically detects your screen's diagonal size, resolution, aspect ratio, pixel density (PPI), color depth, and refresh rate using your browser's APIs. No installation or data upload is required—everything runs locally in your browser. The tool is hosted at whatismyscreensize.com and is maintained by an independent developer (no specific company name is listed).

Key Features

• Real-time detection — Instantly shows your screen's diagonal size (e.g., 15.6"), resolution (e.g., 1920×1080), aspect ratio (e.g., 9:16 Portrait), pixel density (e.g., 141 PPI), color depth (e.g., 24-bit, 16.7 million colors), and refresh rate (e.g., 60 Hz).
• 100% private — No data is collected, stored, or shared; all processing happens in your browser.
• Device database — Browse specifications for hundreds of popular devices including iPhones (iPhone 17e, iPhone 17 Pro Max), iPads, Samsung Galaxy S26 series, MacBooks, ThinkPads, and monitors. Each device page includes screen size, resolution, pixel density, display type, and total pixel count.
• Comparison tool — Compare two or more devices side-by-side on size, resolution, and key specs to aid purchase decisions.
• Additional utilities — Includes tools for viewport measurement, monitor size calculation, pixel density calculation, aspect ratio generation, REM/EM to PX conversion, CSS viewport unit visualization, and responsive breakpoint checking.
• Category browsing — Devices are organized by brand and category (e.g., iPhone, iPad, Galaxy S, Pixel, MacBook, Monitor) for easy navigation.
• Blog with buying guides — Articles like "Best Monitor Size for Developers" and "Best Dual Monitor Setup Size" provide practical advice.

Who is it for?

• Web developers — Check viewport dimensions, pixel ratios, and CSS breakpoints to ensure responsive designs.
• Designers — Verify display specifications (color depth, PPI) for accurate color and layout work.
• Consumers — Compare screen specs of devices like iPhone 17 vs Galaxy S26 before making a purchase.
• Tech enthusiasts — Research display technologies and pixel densities of the latest gadgets.

What can you do with it?

• Check your monitor's physical dimensions — Use the Monitor size calculator to get measurements in inches and centimeters.
• Compare devices — Use the comparison tool to see side-by-side specs of multiple phones, tablets, or laptops.
• Calculate pixel density — Use the Device pixel density calculator for any custom resolution.
• Generate aspect ratios — Use the Aspect ratio generator to find aspect ratios from any width and height.
• Convert CSS units — Use the REM & EM to PX calculator for layout development.

How does it work?

Simply visit the website; the tool automatically reads your screen's specifications via browser APIs. No installation, registration, or data upload is required. The entire process takes place locally on your device.

Pricing

The tool is completely free. All features, including the device database, comparison tool, and additional utilities, are available at no cost.

FAQ

Is What Is My Screen Size free?

Yes, it is entirely free. No payment, registration, or subscription is needed.

Does the tool store my data?

No. All screen detection happens in your browser, and no data is collected or stored on any server. The site is 100% private.

What information does it show?

It currently displays screen diagonal size, resolution, aspect ratio, pixel density (PPI), color depth, and refresh rate for your active display. Additional tools can provide viewport dimensions, monitor physical size, and more.

Can I compare multiple devices?

Yes. Use the comparison tool to select and compare specifications of multiple phones, tablets, or laptops side-by-side.

Does it work on all devices?

It works on any device with a modern browser—desktops, laptops, tablets, and phones. The tool relies on browser APIs that are supported in Chrome, Firefox, Safari, and Edge.