What this page shows
The large number at the top is your screen resolution as the browser reports it. The table adds the details that web designers, developers and support teams ask for most often. The values update when you resize the window, and Copy all details copies the whole table as plain text, ready to paste into a bug report or support chat.
| Screen resolution | The whole screen in CSS pixels, the unit web pages use for layout. |
|---|---|
| Physical pixels (approx.) | Screen resolution × device pixel ratio: usually the panel's real pixel count. |
| Device pixel ratio | How many physical pixels make up one CSS pixel, in each direction. |
| Browser window (viewport) | The inner size of the browser window in CSS pixels, including any scrollbar. |
| Available screen area | The screen minus permanent bars such as the Windows taskbar or the macOS Dock. |
| Color depth | Bits per pixel. 24-bit means 8 bits for each of red, green and blue: about 16.7 million colors. |
| Browser and operating system | Worked out from the user agent string and, in Chrome and Edge, from extra details the browser provides. |
| CPU threads and memory | The number of logical processors. Memory is reported only by Chromium-based browsers, rounded and capped at 8 GB, hence “at least”. |
The remaining rows show the orientation, touch support, preferred languages, time zone, dark-mode preference and whether cookies are enabled. The time zone is the one the Time Zone Converter uses as your home zone.
CSS pixels, device pixels and devicePixelRatio
A CSS pixel is a layout unit, not a dot on the panel. On a basic monitor one CSS pixel is one device pixel, but on phones and high-density laptops several device pixels draw each CSS pixel, so text keeps the same physical size while looking sharper. The relationship is window.devicePixelRatio: 2 on Macs with Retina screens at default settings, 3 on many recent iPhones, and values such as 1.25 or 1.5 on Windows laptops with display scaling.
That is why layouts and media queries work in CSS pixels, and why images need more pixels than their displayed size: a picture shown 400 CSS pixels wide on a screen with a ratio of 2 needs an 800-pixel-wide file to look crisp. The Image Resizer can make those versions.
Examples
- A Full HD laptop at 125% scaling reports 1536 × 864 with a device pixel ratio of 1.25; the physical pixels row shows the real 1920 × 1080.
- A 4K monitor at 150% reports 2560 × 1440 with a ratio of 1.5, and at 200% it reports 1920 × 1080 with a ratio of 2. Either way the physical row shows 3840 × 2160.
- An iPhone 15 reports 393 × 852 with a ratio of 3, which is 1179 × 2556 physical pixels.
- Browser zoom also changes the numbers: in Chrome, Edge and Firefox, zooming to 200% doubles the device pixel ratio and halves the viewport in CSS pixels. If the figures look odd, press Ctrl+0 (⌘+0 on a Mac) to reset the zoom.
The physical figure is an estimate. On a Mac set to a scaled “looks like” resolution, macOS draws the screen at twice that size and then scales it to the panel, so the result can differ from the display's native resolution.
Common screen resolutions
| 1366 × 768 | Older and budget laptops |
|---|---|
| 1536 × 864 | Full HD laptops at 125% scaling, in CSS pixels |
| 1920 × 1080 | Full HD – the most common desktop monitor resolution |
| 2560 × 1440 | QHD / 1440p – popular for gaming and office monitors |
| 3840 × 2160 | 4K UHD – TVs and high-end monitors, usually used with scaling |
| 390 × 844, 393 × 852 | Recent iPhones, in CSS pixels |
| 360 × 800, 412 × 915 | Common Android phones, in CSS pixels |
Privacy
The page reads these values with standard browser features and shows them only to you; nothing is sent anywhere. Any website can read the same information, though, and the combination can help recognise a browser, a technique called fingerprinting. For that reason some privacy-focused browsers round or standardise values such as screen size, and Chrome now shares fewer details in its user agent string.
FAQ
Why does my 4K monitor show 2560 × 1440 or 1920 × 1080?
Your operating system is scaling the display, for example by 150% or 200%, so that text isn't tiny. The physical pixels row shows the panel's real resolution.
Why is the viewport smaller than the screen?
It excludes the browser's tabs and address bar and the system taskbar or Dock, and it changes when you resize the window. On phones it can also change as the address bar slides in and out.
Why does Android show version 10 when my phone runs a newer one?
Chrome on Android reports a fixed Android version in its user agent string to reduce fingerprinting, so the real version can't be read from it.
Why does Windows show “10 or 11”?
Both versions send the same user agent string. Chrome and Edge reveal the difference through an extra browser feature, so in those browsers the exact version appears.
How do I change my screen resolution?
On Windows, open Settings › System › Display and change Display resolution or Scale. On a Mac, use System Settings › Displays. Scaling changes the size in CSS pixels; resolution changes the pixels sent to the monitor.