How to compare a monitor's picture in full-screen mode

One monitor looks warmer, dimmer, or less colorful than another, but windows, toolbars, and different content make it hard to tell why. A full-screen comparison gives you the same colors across the display, without other images competing for your attention.

Use the Screens tool to identify your connected displays and show its color test on each one. This can reveal visible differences, though it cannot measure color accuracy or replace a calibration device.

Compare monitors in full-screen mode

1. Open Screens and check the listed displays. Use their resolution and scale details to identify which screen is which.
2. Move the browser window onto the monitor you want to check. If you have several screens, make sure the window is on the one you intend to test before entering full-screen mode.
3. Open the color test for that display. Look at the colors and gray tones, and note anything that seems unusually dim, tinted, banded, or uneven.
4. Enter the browser's full-screen mode. On many Windows browsers, press F11. On macOS, press Control + Command + F, or use the browser's full-screen command from its menu.
5. Repeat the same check on each monitor. Keep the room lighting and your viewing position as similar as possible, and compare the same parts of the color test.

To leave full-screen mode, use the same shortcut again, or press Esc if your browser or the test responds to it. If the browser fills the wrong monitor, leave full-screen mode, move the window to the correct display, and repeat the check.

What the result means

One screen looks warmer or cooler

A white or gray area may look yellow, blue, or pink on one monitor. A color temperature setting, Night Light, Night Shift, True Tone, or a different monitor picture mode can cause this. It does not automatically mean the screen is damaged.

One monitor looks dimmer

Different brightness settings are a common reason. Automatic brightness, HDR, and power-saving modes can also change how bright a screen appears. Compare the brightness controls before judging the panel itself.

You see a line, patch, or uneven color

First check whether the mark stays in the same place on the physical display as the test changes. A mark that remains in one spot may be a screen defect. A line or patch that moves with the displayed image may instead come from the browser, graphics settings, cable, or signal.

The monitors look similar in the test

The difference you noticed may come from the app, image, or video rather than the monitor. A browser test also cannot tell you whether two screens reproduce a particular color exactly. It is a visual check, not a professional color measurement.

Make the comparison fair

1. Turn off color-shifting features. In Windows 11, open Settings › System › Display › Night light and turn Night light off. On macOS, open System Settings › Displays and turn off Night Shift and, if available, True Tone.
2. Match the brightness. On Windows 11, check Settings › System › Display. On a Mac, open System Settings › Displays. External monitors usually have brightness controls in their own on-screen menu, so use those to bring the screens closer together.
3. Use the same picture mode. Check each monitor's on-screen menu for settings such as Standard, Movie, Vivid, or a low-blue-light mode. Choose the same neutral or standard mode on both, if available. Names and options vary by model.
4. Check HDR and automatic adjustments. In Windows 11, open Settings › System › Display › HDR for a screen that supports HDR. Temporarily turn HDR off if the screens look noticeably different during this comparison. Also disable automatic brightness or contrast if your monitor offers it.
5. Confirm each screen is at its recommended resolution. In Windows 11, go to Settings › System › Display, select a display, and check its resolution. On macOS, open System Settings › Displays and review the resolution options. A non-native resolution can make an image look softer, although it usually does not explain a color tint by itself.
6. Check the signal connection. Reseat the video cable at both ends and try another port if available. If the color issue changes when you move the cable, the connector or cable may be the cause.

When the difference may be a screen fault

If a colored spot or line stays in the same physical location through different colors and after you restart the computer, it may be a stuck or damaged pixel. Use the Display Test to show screen colors and check for dead pixels. For more detail on distinguishing a stuck pixel from a dead one, see stuck pixel vs. dead pixel.

For a new monitor, keep a photo of the visible fault and check the return or warranty terms before trying repair methods. If the display is out of warranty and the mark persists across devices and inputs, a repair shop can tell you whether the panel is worth repairing.

Why full-screen mode helps, and what it cannot do

Full-screen mode removes the browser frame and other desktop content, making it easier to focus on the color test. It does not make the browser bypass the operating system's color profile, the monitor's picture settings, or the limits of the screen itself.

For photo or video work where color must match a standard, visual comparison alone is not enough. A hardware calibrator can measure a monitor and create a profile for it. For everyday use, matching the basic display settings is often enough to make two screens look more alike.