How to check screen identification on a multi-monitor desk

When you use two or more monitors, it can be hard to tell which screen a setting or app is referring to. The numbering may not match the order of the screens on your desk, and two monitors can have the same resolution.

Use the Screens tool to review the displays your browser can see and run a color test on each one. Then compare those results with your computer’s display settings to map each entry to the physical monitor.

Identify each screen

1. Open Screens and review the display entries. Note the resolution and scale shown for each screen. If two entries look alike, that is normal, they may be identical monitors or have the same settings.
2. Open your computer’s display settings. On Windows 11, go to Settings › System › Display. On macOS, open System Settings › Displays. Check how the screens are arranged in the settings.
3. Use the operating system’s screen identification or arrangement view to match each entry with a physical panel. On Windows 11, choose Identify to show a number on each display. On a Mac, compare the display arrangement shown in settings with the physical layout on your desk. If needed, move a window across the screens to confirm which panel it reaches.
4. Return to the Screens tool and run its color test on one display entry at a time. Look at the monitors to see which one shows the test. Repeat for each entry, and write down the match if you manage several screens.

Keep the monitor arrangement in your operating system in mind while testing. A display positioned to the left in settings may be physically on the right, so the mouse pointer can seem to move in the wrong direction until you correct the layout.

What the result means

Each entry matches a different monitor

The screens are being reported separately, and the color test gives you a practical way to connect each entry to a physical panel. If their positions are also correct in display settings, your layout is mapped as expected.

Two entries have the same resolution and scale

This does not mean the computer has mistaken one screen for two. Monitors with the same model or settings often share these values. Use the operating system’s identification view or the Screens color test to distinguish them by physical position, not by resolution alone.

A display appears in settings but not in the tool

The browser may not be able to report every detail of the screen setup, or the display may not be active as a separate desktop. Check that the operating system has detected it and that the screens are extended rather than duplicated. Then reload the page and check again.

The color test appears on a different monitor than expected

The entry may be associated with another physical screen, or the operating system’s arrangement may not match the desk. Identify the monitor by the test result first, then adjust the arrangement in display settings if pointer movement or window placement is wrong.

The number or position changes after reconnecting a screen

Operating systems can assign display numbers or update their layout when monitors are unplugged, docks are connected, or the computer wakes from sleep. Recheck the arrangement after those changes instead of relying on an old number.

Fix a mixed-up screen layout

1. Confirm that every monitor is on. Check its power light and selected input, such as HDMI or DisplayPort. A monitor on the wrong input can look disconnected even when its cable is attached.
2. Identify the panels in system settings. On Windows 11, open Settings › System › Display and select Identify. On macOS, open System Settings › Displays and compare the arrangement shown there with the physical positions on your desk.
3. Arrange the displays to match your desk. In Windows 11 display settings, drag the numbered display boxes so their positions match the monitors. On a Mac, adjust the display arrangement in the Displays settings. This helps the pointer move naturally between panels.
4. Check that the computer is extending the desktop. On Windows 11, use the display mode setting in Settings › System › Display and choose Extend these displays if you want a separate workspace on each monitor. On macOS, review the display use options in System Settings › Displays and make sure the screens are not set to mirror one another if you want separate desktops.
5. Reconnect the display cable or dock. Disconnect and reconnect the cable at both ends, then wait for the operating system to detect the screen. If you use a dock or adapter, test a direct connection when possible.
6. Reload the browser tool. After changing display connections or settings, reload the Screens page and check the entries again. If the setup still looks wrong, restart the computer to make it detect the screens from a fresh start.

What screen identification can and cannot tell you

A screen entry can help you compare reported resolution and scale, but those values do not uniquely identify a monitor. Two panels can share the same resolution, and a screen’s reported size or scaling may differ from the number printed on its box. The color test is useful because it lets you see which physical panel corresponds to an entry.

A browser-based check also cannot determine whether a monitor is connected to the port you intended, or whether its cable supports every display mode. Use the operating system’s display settings for desktop arrangement and the Screens tool to verify which visible panel corresponds to each browser-reported display.