What Is My Screen Size

Browser Viewport0 × 0CSS Pixels
Real-Time Measuring
Display Visualizer

Resize your browser window to watch the viewport dimensions update instantly.

Note

Screen and hardware values remain fixed to your monitor capabilities, while viewport tracks active window space.

Display Specifications

Hardware & Viewport Diagnostics

Screen Size (Logical)
Logical resolution
0 × 0
Physical Resolution
Actual hardware pixels
0 × 0
Device Pixel Ratio (DPR)
Density scale factor
1.00x
Aspect Ratio
Display proportions
0:0
Refresh Rate
Frame frequency
Measuring...
Color Depth
Palette depth
24-bit
Total Pixels
Physical count
0
Screen Orientation
Active layout mode
Portrait

Being aware of the precise screen dimensions and display resolution is crucial whether you are a web developer who wants to test responsive designs, a gamer who wants to tweak display settings or a designer who needs to optimize graphics. Our screen size checker offers a dynamic, click-free measurement of your monitor and browser window properties.

While most similar applications simply reveal the viewport size, ours finds both logical layout dimensions as well as high-resolution physical resolution. This way, it computes the aspect ratio, DPI/PPI, pixel density (DPR) and even your monitor's refresh rate.

Understanding Screen Resolution vs. Viewport

For a seamless online experience, browsers distinguish between your hardware's full potential and the active space where content is displayed:

  • Logical Screen Size: The actual size of the working desktop area expressed in CSS pixels. This dimension will not change whether you resize the browser window or minimize it.
  • Physical Resolution: The actual number of pixels in the monitor hardware that you use. It is calculated by multiplying the logical pixels with your Device Pixel Ratio.
  • Browser Viewport: The actual window size displaying the web page at the present moment. Resizing the browser window changes the viewport size immediately.
  • Refresh Rate: The actual rate at which your screen updates itself every second.

How Device Pixel Ratio (DPR) & High-DPI Scaling Works

High density displays are employed by modern devices for the presentation of sharp texts and clear graphics. Rather than assigning each layout unit to a single physical LED, a high DPI display combines several physical pixels for the creation of one logical CSS pixel.

For example, an item that is set to have a DPR of 2.0 uses four pixels physically (i.e., a 2x2 matrix) in order to display one pixel logically. This helps prevent any website text from being too small due to its higher resolution screen.

Why Diagnostic Display Metrics Matter?

Access precise hardware and layout properties to optimize games, test layouts, and review device fidelity.

Instant Automated Detection

No need to click anything or configure. As soon as you load the page, the tool automatically fetches and shows all screen, viewport, and display information.

High-DPI & Retina Support

Automatically detects your Device Pixel Ratio (DPR) and displays both CSS Layout Size and Hardware Resolution.

Live Viewport Tracking

Browser resizing events live-update viewport metrics, enabling web developers/designers to assess responsive designs easily.

Monitor Refresh Rate Detection

Performs an advanced performance test via requestAnimationFrame to determine the refresh rate of your screen in Hz.

Orientation & Aspect Ratios

Determines your screen's orientation (either Landscape or Portrait) and reduces pixel dimensions to common aspect ratios (16:9, 16:10, 4:3).

Privacy-Focused

Calculations are done entirely in your browser using JavaScript. No screen specifications or personal device data are ever sent to our servers.

Find clear answers to high-volume search questions regarding browser scaling, hardware pixels, and display aspect ratios.

Common Questions About Screen Size & Resolutions

The physical resolution is the real resolution of the hardware on your computer (for example, 3840 x 2160 in the case of a 4K screen). The logical screen resolution is the one measured in CSS pixels (for example, 1920 x 1080) used by web browsers to display page layouts.
Your viewport is the part of your screen on which actual content appears, excluding parts like browser chrome, scroll bars, tool bars, etc. Due to the space taken by such elements, your viewport will always be smaller than your screen resolution.
No, changing your browser zoom level does not change your hardware screen size or its native resolution. However, when you zoom in, the logical width and height of your viewport decrease (making things appear larger), and when you zoom out, they increase.
A web browser cannot ask your computer about the actual diagonal dimension of your monitor (e.g., 15.6" or 27") since this hardware information is not accessible through browser API functions due to privacy considerations. You can check the specifications of your monitor or measure it diagonally by hand.
The aspect ratio shows the proportional relationship between the width and height of your display. The tool calculates this by finding the greatest common divisor (GCD) of the screen's width and height and then reducing both dimensions by that number to get standard ratios such as 16:9, 16:10, or 4:3.
The Device Pixel Ratio is the ratio of physical hardware pixels to logical CSS pixels. If the DPR is 2.0 (also known as Retina or HiDPI), four hardware pixels (2x2) will be required for each logical pixel. This will result in very crisp graphics.
Physical pixels are the microscopic light-emitting diodes on your screen. CSS pixels are abstract units used by developers for sizing web layouts. On standard displays, 1 CSS pixel equals 1 physical pixel, but on modern high-density displays, 1 CSS pixel maps to multiple physical pixels depending on the device scaling factor.
It depends on the number of pixels per inch (PPI), meaning how many physical pixels fit into one inch of screen space. If two laptops have the same physical size of 15.6 inches, but one has a 4K screen and another 1080p, then the first one will be much sharper due to its higher PPI.
By default, in Windows you can enable display scaling (such as 125% or 150%) in Windows Settings, which means that logical size of the screen becomes smaller than its actual size, decreasing the number of screen width and height pixels.
No, screen size and resolution are generic hardware properties that do not contain personal details. However, screen properties are often used alongside other browser characteristics (like fonts and user agent) in a technique called "browser fingerprinting" to build a unique device profile.

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Disclaimer

The display specifications provided by the What Is My Screen Size tool are retrieved directly from standard browser APIs. Physical diagonal monitor sizes are estimates only, as hardware APIs do not share physical panel measurements for privacy reasons.