What Is My Screen Resolution - Check Display
Instantly see your screen resolution, browser viewport size, device pixel ratio, and color depth. Useful for responsive design testing and display troubleshooting.
Your Screen Information
- Screen Resolution
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- Viewport Size
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- Color Depth
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- Pixel Ratio
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Understanding This Tool
What It Does
This tool reads four display-related values directly from your web browser using JavaScript that runs in your browser, not on our server. It reports your screen's logical resolution (screen.width and screen.height), the current browser viewport size (window.innerWidth and window.innerHeight), the screen's reported color depth (screen.colorDepth), and the device pixel ratio (window.devicePixelRatio). The numbers describe the browser window and the display surface the browser is drawing to, so they can change if you resize the window, move the browser to another monitor, or change your operating system display scaling.
Understanding the Results
- Screen Resolution: Shows screen.width by screen.height, the logical (CSS-pixel) size of your display as the browser sees it. On high-DPI or scaled displays this is not the native hardware pixel count, so to estimate the physical pixels, multiply each value by the Pixel Ratio below.
- Viewport Size: Shows window.innerWidth by window.innerHeight, the area of the browser window currently available for the page (including any space taken by scrollbars). This is usually smaller than the screen resolution and reflects the window size at the moment the page loaded.
- Color Depth: Shows screen.colorDepth followed by the word "bits", the number of bits the browser reports for representing colors. Most modern displays report 24 bits (about 16.7 million colors).
- Pixel Ratio: Shows window.devicePixelRatio, the ratio of physical device pixels to CSS pixels. A value of 1 is a standard-density display; 2 or 3 indicates a high-DPI (Retina-style) screen. This value also changes with browser zoom level.
Common Use Cases
- Responsive design testing: Resize your window, reload the page, and read the viewport size to see which CSS breakpoint is active at a given width.
- Confirming high-DPI rendering: Check the device pixel ratio to know whether a screen is high-density, which affects how sharp images and 1x versus 2x assets will appear.
- Display and scaling troubleshooting: Compare the reported resolution and pixel ratio against your expectations to spot operating-system display scaling or browser zoom that is changing the numbers.
- Bug reports and support tickets: Copy your screen resolution, viewport, color depth, and pixel ratio into a report so a developer can reproduce a layout issue on a matching window size.
- Verifying multi-monitor setups: Move the browser to another monitor, reload the page, and compare the values to see how each display's resolution and pixel ratio differ.
Pro Tips & Best Practices
- Resolution is logical, not physical: On scaled or Retina displays the screen resolution shown is in CSS pixels. Multiply by the Pixel Ratio for a rough estimate of the native hardware pixel count.
- Zoom changes the numbers: Browser zoom affects both the viewport size and the device pixel ratio. Set zoom to 100 percent if you want values that reflect your actual display rather than your zoom level.
- Viewport is not the full screen: The viewport size excludes browser toolbars, the OS taskbar, and window borders, so it is normally smaller than the screen resolution even when the window is maximized.
- Reload after changes: The values are read once when the page loads. Resize the window, move monitors, or change scaling, then reload the page to see updated numbers.
Frequently Asked Questions
Not necessarily. It shows the logical resolution the browser reports through screen.width and screen.height, measured in CSS pixels. On high-DPI or scaled displays this is smaller than the native hardware pixel count. To estimate the physical pixels, multiply each dimension by the Pixel Ratio value.
The viewport is only the part of the browser window where the page is drawn. It excludes browser toolbars, the operating system taskbar, and window borders, so it is normally smaller than the full screen resolution even when the window is maximized.
It is window.devicePixelRatio, the number of physical device pixels per CSS pixel. A value of 1 means a standard-density display, while 2 or 3 indicates a high-DPI screen such as a Retina display. Browser zoom also changes this value, so it can be a non-whole number when you are zoomed in or out.
No. All four values are read in your browser by JavaScript and displayed directly on the page. The tool does not transmit your screen resolution, viewport, color depth, or pixel ratio to our server to produce these results.
The numbers are read once when the page loads, so they do not update on their own. Resizing the window changes the viewport size, and moving the browser to a different monitor or changing display scaling can change the resolution and pixel ratio. Reload the page to see the updated values.
Frequently Asked Questions
Does this show my monitor's true native resolution?
Not necessarily. It shows the logical resolution the browser reports through screen.width and screen.height, measured in CSS pixels. On high-DPI or scaled displays this is smaller than the native hardware pixel count. To estimate the physical pixels, multiply each dimension by the Pixel Ratio value.
Why is my viewport size smaller than my screen resolution?
The viewport is only the part of the browser window where the page is drawn. It excludes browser toolbars, the operating system taskbar, and window borders, so it is normally smaller than the full screen resolution even when the window is maximized.
What does the pixel ratio mean?
It is window.devicePixelRatio, the number of physical device pixels per CSS pixel. A value of 1 means a standard-density display, while 2 or 3 indicates a high-DPI screen such as a Retina display. Browser zoom also changes this value, so it can be a non-whole number when you are zoomed in or out.
Is my screen information sent to your server?
No. All four values are read in your browser by JavaScript and displayed directly on the page. The tool does not transmit your screen resolution, viewport, color depth, or pixel ratio to our server to produce these results.
Why don't the values update when I resize or move the window?
The numbers are read once when the page loads, so they do not update on their own. Resizing the window changes the viewport size, and moving the browser to a different monitor or changing display scaling can change the resolution and pixel ratio. Reload the page to see the updated values.
Last reviewed:
How this tool works: This tool runs in your browser and on our server in real time. Depending on the tool, results are computed directly from the input you provide or retrieved from live, authoritative data sources at the moment you run a lookup. We do not sell your data, and your lookups are kept private — any history shown here is stored only on your device.