What Is My Screen Resolution

What is my screen resolution? Real pixels and the size the web uses, side by side

This screen resolution checker reads your device's screen values the moment the page opens and shows the resolution in real pixels, largest of all. Many resolution sites print the CSS pixel value the browser reports and call it the resolution, which is why a 1920 × 1080 monitor often shows up as 1536 × 864. This tool multiplies the operating system scale back in to recover real pixels, and in browsers such as Chrome and Edge, where the zoom step can be worked out from the window sizes, it also removes browser zoom from the calculation.

The screen plan under the answer draws the whole screen, the taskbar, the browser window and the area where the page is actually visible, all to scale. When you resize the window or move it, the plan follows, so you can see right away what each number refers to. The same page also gathers how dense the pixels are, which color gamut and HDR the screen reports it can show, and which operating system, browser and graphics chip you have, in one table. Everything is calculated inside this browser and is never stored or sent.

When to check your screen resolution

• After connecting a new monitor or laptop: even a 4K monitor can end up at a lower resolution because of the cable or settings. Check first that the real pixels match the monitor's specification.
• When text looks blurry or too small: a resolution that is not the recommended one blurs text, and a scale that is too low shrinks it. Looking at resolution and scale together tells you which one is the problem.
• When picking game or video quality: choosing 4K video on a QHD monitor, or a QHD game resolution on an FHD monitor, means a picture larger than the screen is scaled down. Matching the real pixels of the screen is the baseline.
• When a web page is cut off or looks broken and you need to report it: support teams and developers usually ask for the resolution, scale, browser and window size. Copy result puts these values into text in one step.
• When building or testing responsive pages: layout changes with the CSS width of the visible area, not with real pixels. Narrow the window and watch the plan and the visible area numbers to see which width you are on.
• Before photo or video work, to check the color gamut and HDR: wide-gamut (P3) photos and HDR video only look right when both the screen and the browser support them.
• When buying or selling a used laptop or monitor: you can confirm on the spot that the resolution in the listing matches the real screen and that the graphics details are right.

How to check your screen resolution

1. Open this page on the screen you want to check. With several monitors, move the browser window to the monitor you want to check.
2. Read the big number at the top. That number is the real resolution of the screen. The tag under it shows the resolution name, aspect ratio and megapixels, and the sentence below tells you how many pixels the web sees because of scaling.
3. Look at the four small tiles on the right. They show the size on the web, the scale (DPR), the browser zoom and the visible area, in that order. If zoom is not 100%, press Ctrl+0 (⌘+0 on a Mac) to reset it and look again.
4. Move the window on the screen plan. When you resize or move the window, the window and the visible area move with it on the plan. The "Real pixels" and "CSS pixels" buttons switch the unit of the plan numbers.
5. With several monitors, press "Show all monitors". In Chrome and Edge, once you allow access, the monitor layout appears along with each monitor's name, resolution and scale.
6. If you like, enter the screen diagonal in inches. It calculates pixel density (PPI), the screen's width and height, and the dot pitch.
7. Press Copy result. Resolution, scale, window size, color, operating system, browser and graphics are copied as text, ready to paste into a support message or a note.

How to read the numbers: real pixels, CSS pixels, scale

A screen has two sets of numbers: real pixels, the count of dots on the monitor panel, and CSS pixels, the unit web pages use to measure size. The CSS pixel was originally defined as the size of one dot on a 96 dpi screen, so on a screen with denser dots one CSS pixel is drawn with several real pixels. That ratio is the scale (devicePixelRatio, DPR), and it is the operating system scale setting multiplied by browser zoom.

Real pixels = CSS pixels × OS scale = CSS pixels × scale (DPR) ÷ browser zoom

The table below works through how scale changes the numbers. Because the browser reports CSS sizes rounded to whole numbers, a fractional scale leaves the product a few pixels off. This tool picks the standard resolution value (1080, 1366, 1440 and so on) that falls inside that margin.

In Chromium-based browsers such as Chrome and Edge, applying zoom raises the scale, but the screen size the browser reports and the outer window size stay the same (Roberin checked this on 2026-11-01 at 50%, 125% and 200% zoom). Dividing the outer window size by the inner size therefore reveals the zoom step, and this tool subtracts it to calculate real pixels only when width and height point to the same step. A side panel or developer tools docked next to the page narrow only the width and look like zoom, so the tool usually leaves the zoom as "Unknown" in that case, though on rare occasions it can read a different step. Firefox and Safari do not allow this method, so the tool shows zoom as "Unknown" and uses the scale as is. The most accurate values come with zoom at 100% and side panels closed.

Resolution names and aspect ratios: HD, FHD, QHD, 4K

Names like FHD, QHD and 4K are shorthand for fixed pixel counts. The drawing below overlays four common resolutions at the same scale: FHD has 2.25 times the pixels of HD, and 4K UHD has exactly 4 times the pixels of FHD. If the table has a resolution matching this screen, that row is marked "This screen".

The aspect ratio is the ratio of the long side to the short side. 1366 × 768 is not exactly 16:9 but is so close that it is called 16:9, while ultrawides sold as 21:9, such as 2560 × 1080 and 3440 × 1440, actually measure 2.37:1 and 2.39:1. Phones are named by their tall shape, with 1080 × 2340 called 19.5:9 and 1080 × 2400 called 20:9. "4K" also differs between TVs and monitors at 3840 × 2160 (UHD) and cinema at 4096 × 2160 (DCI 4K), so the 4K in a monitor specification is usually 3840 × 2160.

Screen size in inches and pixel density

At the same resolution, a bigger screen has sparser dots. Pixel density (PPI) is the diagonal pixel count divided by the diagonal in inches, and entering the inches in the screen diagonal field of the workspace gives this screen's PPI and its width and height. The browser does not report the physical size of the screen, so you have to enter the inches yourself.

PPI = √(width² + height²) ÷ diagonal in inches · width (cm) = diagonal × 2.54 × width ÷ √(width² + height²)

On a 27-inch monitor, FHD is about 82 PPI, QHD about 109 PPI and 4K about 163 PPI. The denser the dots, the smoother the text, but at 100% scale the text gets smaller, so the denser the screen, the higher the operating system scale you tend to use. The pixel magnifier tile shows how a 1px CSS line is split across two device pixels when the scale is not a whole number. That is why very thin lines and small text can look slightly soft at 125% and 150% scale.

Where to check in the operating system

If this tool's values differ from what you expect, check the resolution and scale directly in your operating system settings. The resolution marked "Recommended" in the settings screen is usually the panel's real resolution.

A Retina Mac reports a scale of 2, so this tool multiplies the screen size the browser reports by 2. That size follows the resolution chosen in Displays settings, so it can differ from the panel's pixel count. When Roberin checked on a 14-inch MacBook Pro, System Information showed a panel resolution of 3024 × 1964, but with a resolution wider than the default selected, the browser reported the screen as 1800 × 1169 and this tool showed 3600 × 2338. To confirm the panel's pixel count too, look at the graphics and displays entries in Apple menu > System Settings > General > About > System Report.

How to read color gamut and HDR

The drawing in the color gamut tile shows three triangles, sRGB, Display P3 and Rec. 2020, over the whole range of colors people can see (the horseshoe shape). The wider the triangle, the more saturated the reds and greens a screen can show, and the widest triangle the browser reports for this screen is filled with the accent color. Common office monitors usually come out as sRGB, while Macs and iPhones that support P3, and wide-gamut monitors, come out as P3.

• How the wide color test works: the background of the two boxes is the most saturated red and green in sRGB, and the letters are the P3 colors of the same names. On an sRGB screen the P3 colors collapse to the closest color it can show, which is the background color, so the letters disappear. On a P3 screen the letters stand out, more saturated than the background.
• HDR: if the browser reports this screen as high dynamic range (dynamic-range: high), it shows "Supported". On Windows, an HDR monitor can still show as standard range when HDR is off in the display settings, so check turning HDR on first in that case.
• Color depth: by specification, a browser may return 24 bits when it does not know the color depth or wants to hide it. A reading of 24 bits can therefore still be a 10-bit panel, and 30 bits means it draws 10 bits per color.

What a browser can tell you about your device, and what it can't

Many people search for "check my computer specs", but the device information a web page can read is deliberately coarse. Treat the values in the table below as a reference only, and check the exact specifications on the operating system screen.

Common mistakes

• Reading CSS pixels as the resolution: an FHD laptop at 125% scale looks like 1536 × 864 to the web. You do not need a different monitor, it just has scaling applied.
• Measuring with browser zoom on: zooming changes the scale and the visible area together. Firefox and Safari do not report zoom, so reset it with Ctrl+0 (⌘+0) and then look.
• Measuring on the wrong monitor: this tool measures the screen the window is currently on. To check a second monitor, move the window there.
• Reading a Mac's value as the panel's pixel count: if you choose a non-default resolution in Displays settings, the size macOS draws can be larger or smaller than the panel.
• Enlarging the display size on a phone: on Android, enlarging screen zoom or display size keeps the real pixels and raises the scale, so only the web size gets smaller. The iPhone's Display Zoom (Larger Text) draws the screen at a smaller size and then enlarges it, so this tool's values can also come out smaller than the device specification.
• Opening the page in an in-app browser: in-app browsers, such as those inside social or messaging apps, can show a different browser name and some different values. Open the page in your default browser to see accurate values.

Limits

• A browser does not report the physical size of the screen in inches. Inches and PPI are calculated from the value you enter.
• Browser zoom is worked out from window sizes only in Chromium-based browsers such as Chrome and Edge. Docked developer tools or side panels are usually treated as "Unknown", but they can rarely be read as a different zoom step, so for an exact measurement set zoom to 100% and close the panel.
• With several monitors, the layout and names of all monitors appear only after you allow access in Chrome or Edge. Without that permission, the taskbar position in the plan is an estimate.
• The exact size of window borders and toolbars cannot be known, so the plan draws the visible area inside the window assuming equal borders on both sides.
• CPU, memory and graphics values are reduced or hidden by browsers to prevent fingerprinting. Check the exact specifications in the operating system.
• Browsers with strong privacy settings may deliberately alter the screen size and device values they report.

As of The settings menu names and source documents were checked on 2026-11-01. Menu names and the values reported can change when operating systems and browsers update.

Sources

• 01MDN: Window.devicePixelRatioRatio of real pixels to CSS pixels; page zoom changes the value, pinch zoom does not
• 02MDN: Screen.availHeightScreen size is in CSS pixels; the usable area excludes the Dock, menu bar and taskbar
• 03W3C: CSS Values and Units Level 41px = 1/96 inch, the reference pixel of a 96 dpi screen viewed at arm's length
• 04MDN: Window.innerWidthThe visible area width includes the width of the vertical scrollbar
• 05W3C: CSS Color Module Level 4Red, green and blue coordinates of the sRGB, display-p3 and rec2020 color spaces
• 06MDN: dynamic-range and color-gamut media featuresMedia queries that report high dynamic range (HDR) and the sRGB, P3 and Rec. 2020 gamuts
• 07W3C: CSSOM ViewReturns 24 when the color depth is unknown or hidden
• 08MDN: Window.getScreenDetails()Layout, names and main-monitor flag of several monitors; window-management permission; since Chrome 100
• 09Microsoft Learn: Detect Windows 11 using User-Agent Client HintsplatformVersion major 13 or higher = Windows 11, 1 to 10 = Windows 10
• 10Chromium: User-Agent ReductionUA string frozen at macOS 10_15_7, Windows NT 10.0 and the Android device model K
• 11WebKit Bugzilla 298473Safari freezes the iOS version in the UA at 18.6 (18.6.2) permanently to reduce fingerprinting
• 12MDN: Navigator.deviceMemoryMemory rounded to a power of 2, with upper and lower bounds set by the implementation (2 to 32 GB from Chrome 147)
• 13MDN: WEBGL_debug_renderer_infoGraphics chip name, blocked or reduced depending on privacy settings
• 14WebKit source: NavigatorBase.cppReports the core count only as 4 or 8 to reduce fingerprinting
• 15W3C: Mitigating Browser Fingerprinting in Web SpecificationsWindow size and device traits can be used to fingerprint a browser
• 16Microsoft Support: Change your screen resolution and layout in WindowsDisplay resolution, the Recommended label and Scale paths (Windows 11 and 10)
• 17Microsoft Support: HDR settings in WindowsSettings > System > Display > HDR; Windows HD Color settings on Windows 10
• 18Microsoft Support: Find information about your Windows deviceProcessor and installed RAM under Settings > System > About, Device specifications
• 19Microsoft: How to check your GPUTask Manager > Performance > GPU, with the graphics chip name at the top right
• 20Mac User Guide: Change your display's resolutionPick a resolution in System Settings > Displays; Show List
• 21Mac User Guide: View About settingsChip, memory and displays under System Settings > General > About; System Report
• 22iPhone User Guide: Adjust display and text size settingsAppearance > Display Zoom > Larger Text
• 23Samsung US: Change the screen resolution on your Galaxy phoneSettings > Display > Screen resolution (HD+, FHD+, QHD+), Screen zoom; menus differ by model
• 24Pixel Phone Help: Change display and screen settingsDisplay & touch > Display size and text
• 25Chrome Help: Chrome keyboard shortcutsCtrl + 0 (⌘ + 0 on a Mac) = reset everything on the page to its default size
• 26Firefox Help: Font size and zoomClick the zoom percentage in the address bar to reset to the default zoom level

Frequently asked questions

Tools to use with this one