What Is My Screen Resolution?
Detect your current screen resolution, device pixel ratio, and advanced system hardware properties instantly.
Standard Device Comparisons
See how your screen width compares to standard design viewports.
Advanced System Metrics
Browser environment details and estimated hardware capabilities. Used by websites to tailor rendering performance.
All diagnostics run locally in your browser. None of your system specifications are sent to any server.
How screen resolution detection works
Screen resolution is the total number of physical pixels your monitor or display renders, reported by the browser via window.screen.width and window.screen.height. This is different from your browser's viewport (window.innerWidth / innerHeight), which is only the visible page area inside the browser chrome — smaller than the full screen once you subtract toolbars, tabs, and the taskbar.
The Device Pixel Ratio (DPR) bridges CSS pixels and physical pixels: on a standard 1x display, one CSS pixel equals one physical pixel, while on Retina/HiDPI displays the DPR is typically 2x or 3x, meaning each CSS pixel is drawn using 4 or 9 physical pixels respectively. Multiplying the viewport size by the DPR gives the actual physical pixel count the browser is rendering — useful when exporting pixel-perfect screenshots or serving correctly sized responsive images.
Color depth reports how many bits are used per pixel to represent color — 24-bit (16.7 million colors) is standard on virtually all modern displays. All of this data is read directly from your browser's screen and window objects; nothing is uploaded or logged, which is why the values update instantly and only in your own browser session.
Built and maintained by Meet Shah · Last updated
What this tool is used for
- Reading your screen resolution and viewport size together.
- Checking the device pixel ratio before exporting an asset.
- Confirming what resolution a display is actually running at.
- Getting a figure to quote in a bug report.
- Comparing two machines' reported values.
Frequently Asked Questions
- Which number is my real resolution?
- The physical one — `screen.width` multiplied by the device pixel ratio. `screen.width` alone reports CSS pixels, which is why a 3840-pixel monitor at 200% scaling reports 1920 and a phone reports far less than its advertised specification.
- What does available screen space mean?
- `availWidth`/`availHeight` — the screen minus permanently reserved areas such as a taskbar or macOS menu bar. It is the largest a maximised window can actually be, which is usually what you want when positioning one.
- Why is the viewport smaller than the screen?
- The viewport excludes browser chrome — tab strip, address bar, bookmarks, scrollbar — and any part of the screen your window does not occupy. On a maximised window the difference is roughly the height of the browser's own interface.
- What is pixel depth?
- Bits per pixel for colour, almost always 24 — eight bits each for red, green and blue. It is a legacy property from when 8- and 16-bit displays were common, and today it tells you very little.
- Is this fingerprinting me?
- The values shown are readable by any page you visit, which is the point of displaying them: resolution, pixel ratio, core count, timezone and language are all standard fingerprinting inputs. Nothing here is transmitted — it is read and rendered locally.
- Why do orientation and touch matter?
- Because they distinguish a tablet from a small laptop far better than width does. `maxTouchPoints` above zero means a touch-capable device, and the screen orientation type tells you whether the current reading is a rotated one.
Common errors and gotchas
- Reading the CSS pixel figure as the physical resolution, which the pixel ratio separates.
- Assuming the OS is not scaling, which most high-density displays do by default.
- Confusing the screen with the available screen area, which excludes taskbars and docks.
- Reporting the viewport as the resolution in a bug report, which are different numbers.
- Assuming a multi-monitor setup reports the display the window is on, which varies.