What is my screen resolution? Resolution and scaling explained

How to check your screen resolution

Your screen resolution is the number of pixels your display shows, written as width × height, for example 1920 × 1080. The quickest way to find it is the screen resolution checker, which reads it straight from your browser with nothing to install.

Here are your screen's numbers right now, read from this browser:

1. Open the screen resolution checker on the screen you want to check. With more than one monitor, drag the browser window onto that screen.
2. Reset browser zoom to 100% with Ctrl+0 (Cmd+0 on a Mac). Zoom changes the numbers.
3. Read Screen resolution, which is in CSS pixels, and Physical pixels, which is the real pixel count.
4. Check Pixel ratio. A value of 1 means one CSS pixel per physical pixel. Above 1 means display scaling, browser zoom or a high-density screen.
5. Use Copy summary if you need to paste the details into a support ticket or forum post.

The page also shows the browser viewport, the area left after the taskbar or dock, aspect ratio, colour depth and whether the browser reports HDR. Every value updates live if you resize, zoom or move the window.

Why does my browser show a lower resolution than my monitor?

Browsers lay pages out in CSS pixels, not physical pixels. When your operating system scales the display up so text is readable, each CSS pixel covers more than one physical pixel, and the browser reports the smaller CSS size.

For example, a 2560 × 1440 monitor with Windows scaling at 150% reports 1707 × 960 CSS pixels and a device pixel ratio of 1.5. Multiply them back and you get the native 2560 × 1440. The screen resolution checker does that multiplication for you and shows it as Physical pixels.

That figure is rounded, so with fractional scaling it can be a pixel or two off. Phones sometimes report a scaled size rather than the panel's native one, so check the maker's spec sheet if the number looks odd.

Native pixels on the panel

2560 × 1440

Pixel ratio at 150% Windows scaling

1.5

CSS pixels the browser reports (2560 ÷ 1.5, 1440 ÷ 1.5)

1707 × 960

Resolution vs display scaling

Resolution is how many pixels the panel has. Scaling is how big things are drawn on those pixels. They're separate settings, and mixing them up is the most common source of confusion.

• Windows: scaling is a percentage, such as 100%, 125% or 150%. At 150%, a button that would be 100 pixels wide is drawn 150 physical pixels wide. Your resolution doesn't change, but apps see less space.
• macOS: Retina Macs draw everything at twice the density and let you pick a size that "looks like" a lower resolution. A Mac set to look like 1440 × 900 still uses every physical pixel, so text stays sharp. The browser reports the looks-like size and a pixel ratio of 2.
• Phones: almost all phones use a pixel ratio of 2 to 3 or more, so the CSS size is far below the panel's real resolution.

For the sharpest image, keep the resolution at your monitor's native value and change scaling to make things bigger or smaller. Running an LCD below its native resolution makes the image soft, because the panel has to stretch it.

What are CSS pixels and device pixel ratio?

A physical pixel is one dot on the panel. A CSS pixel is the unit web pages use to size text and layout. The device pixel ratio is how many physical pixels make up one CSS pixel along each side.

At a ratio of 1, they're the same. At 2, each CSS pixel is a block of 2 × 2 physical pixels, so text and images can be drawn with more detail at the same size. Browser zoom changes the ratio too: zooming to 200% on a ratio-1 screen gives a ratio of 2, which is why the numbers jump when you zoom.

1080p vs 1440p vs 4K

• 1080p (Full HD): 1920 × 1080, about 2.1 million pixels. Common on budget monitors, laptops and high refresh rate esports monitors. Looks sharp up to about 24 inches at desk distance.
• 1440p (QHD): 2560 × 1440, about 3.7 million pixels, roughly 1.8 times 1080p. A popular choice for 27-inch gaming monitors, balancing sharpness and frame rate.
• 4K (UHD): 3840 × 2160, about 8.3 million pixels, exactly four times 1080p. Common on 27 to 32-inch monitors and TVs. Very sharp, usually with scaling at 150% or more on a desktop.

The same resolution looks sharper on a smaller screen, because the pixels are packed closer together. Work it out for any monitor below.

More pixels means a sharper image but more work for the graphics card in games. A card that runs a game at 144 FPS at 1080p will run it much slower at 4K. If a high refresh monitor feels sluggish, check it's really running at its rated rate with the refresh rate test.

Aspect ratios: 16:9, 16:10 and 21:9

Aspect ratio is the shape of the screen, width compared to height.

• 16:9 is the standard for monitors, TVs and video: 1920 × 1080, 2560 × 1440, 3840 × 2160.
• 16:10 is a little taller, which suits documents and code. It's common on laptops and some office monitors: 1920 × 1200, 2560 × 1600.
• 21:9 is ultrawide: 2560 × 1080 and 3440 × 1440 are typical. It suits games that support it and having several windows side by side. Most video still has black bars on the sides.

The checker shows the aspect ratio your browser reports. If it doesn't match your monitor, the resolution is probably set to a non-native value.

How to change your screen resolution

• Windows 11: Settings > System > Display. Choose Display resolution and pick the one marked Recommended, which is your monitor's native resolution. Change Scale on the same page to make things bigger or smaller.
• Windows 10: Settings > System > Display. Use Display resolution under Scale and layout, and change the size of text, apps and other items for scaling.
• macOS: System Settings > Displays. Pick one of the size options for your display. On a Retina screen these change the looks-like size, not the physical pixels.

If your native resolution isn't in the list, update your graphics driver and check the cable. An old HDMI cable or adapter can limit the resolution and refresh rate together. After any change, reload the screen resolution checker to confirm it took effect.

Next, check the rest of your display

Once the resolution is right, check the panel itself. Run the dead pixel test to look for dead and stuck pixels, use the screen test for backlight bleed, banding and uneven brightness, and confirm your monitor's refresh rate with the refresh rate test. If it's stuck at 60Hz, our guide to a 144Hz monitor showing 60Hz walks through the fixes, and the motion blur guide covers ghosting.