Windows gives you several ways to adjust screen brightness, but the correct method depends on whether you are using a laptop, an all-in-one PC, or a separate monitor. On Windows 11, the fastest route is the Network icon in the taskbar. You can also use Display settings, automatic brightness controls, keyboard keys, or—when Windows cannot control the screen—the monitor’s physical buttons. Adjust brightness quickly in Windows 11 For a laptop or other PC with a supported built-in display: Select the Network icon on the right side of the taskbar. This opens Quick Settings. Find the Brightness slider. Drag the slider left to dim the screen or right to make it brighter. You may need to select the small arrow or expand Quick Settings before the slider is visible. The Windows 11 control is accessed through the Network icon—not the old Windows 10 “Action Center” label. Use Windows 11 Display settings The full settings page provides the brightness control and related automatic-adjustment options: Outdated Drivers Are Slowing You Down One free scan finds every outdated or missing driver and matches the right update for your exact hardware. Open Start and select Settings . Go to System > Display . Under Brightness and color , move the Brightness slider. This is also the place to configure Night light and, on supported computers, adaptive brightness behavior. Turn on automatic brightness in Windows 11 Some laptops contain an ambient-light sensor that can adjust the display when room lighting changes. To enable it, open Start > Settings > System > Display > Brightness , then turn on brightness automatically when lighting changes . The option is hardware-dependent, so it will not appear on every Windows 11 PC. The manual brightness slider can remain available even when automatic adjustment is unsupported. On HDR displays, the change may take longer after the lighting changes because Windows optimizes the result for perceived brightness. Stop Windows from changing brightness based on screen content Some Windows 11 PCs can change brightness and contrast when the content on the built-in display changes. This is separate from adjustment based on room lighting. For example, the display may react differently to a bright webpage and a dark video. Recommended Free Tools Outdated Drivers Are Slowing You Down PC Slower Than It Used to Be? Crashes, No Sound, or Screen Glitches? Open Start > Settings > System > Display . Expand or open the Brightness section. Find Change brightness based on content . Choose one of these options: Off — disables content-based adaptive brightness. Always — allows the feature on both battery and AC power. On Battery Only — uses it only when the PC is running from its battery. Off — disables content-based adaptive brightness. Always — allows the feature on both battery and AC power. On Battery Only — uses it only when the PC is running from its battery. Choose Off if brightness or contrast keeps shifting while you work. Adaptive behavior can help battery life, so disabling it may increase power consumption. Adjust brightness in Windows 10 On Windows 10 version 1903 and later, select the Action center icon on the right side of the taskbar and move the Brightness slider. On earlier Windows 10 releases, or when the Quick Settings control is unavailable: Open Settings . Select System > Display . Move the Change brightness slider. Windows 10 reached the end of normal Microsoft support on October 14, 2025 . It continues to run, but Microsoft no longer provides the standard free Windows Update software updates, technical assistance, and security fixes associated with normal support. Crashes, No Sound, or Screen Glitches? Use the keyboard brightness keys Many laptops have brightness icons on the function row, usually showing a sun with a smaller or larger circle. Press the dim or brighten key. On some models, you must hold Fn while pressing it; on others, the function row is configured to use brightness directly. The exact key combination depends on the laptop manufacturer. If the keys do nothing, try: Fn plus the key marked with the dim or bright sun icon. The laptop manufacturer’s keyboard or hotkey utility. Windows Settings as a test. If Settings works but the keys do not, the problem is likely the hotkey driver or utility rather than Windows brightness control itself. Change brightness on an external monitor Windows may not show a Brightness slider when the PC is connected to a separate external monitor. This is expected on many desktop setups because the monitor controls its own backlight. Use the buttons, joystick, or touch controls built into the monitor. The usual menu is similar to: What’s actually slowing this PC down?

Pick the symptom - the matching free tool is one click away. Press the monitor’s Menu or joystick button. Open Picture , Image , or a similarly named menu. Select Brightness . Increase or decrease the value, then exit the menu. Do not confuse Brightness with Contrast : brightness normally controls the backlight level, while contrast changes the difference between light and dark tones. Menu names vary by monitor. Set brightness with PowerShell Microsoft documents a WMI method for setting brightness on compatible displays. It is mainly useful for scripting or automation and is not a universal solution for external monitors. Open Windows PowerShell and run this Microsoft-documented Windows PowerShell example to set brightness to 50 percent: In this example, $brightness is a percentage from 0 to 100, and $delay is the timeout in seconds. A return value of 0 indicates success; another value indicates an error. Quick wins for a faster PC: Get-WmiObject is the legacy Windows PowerShell command shown in Microsoft’s brightness-method documentation. Microsoft says it was superseded by Get-CimInstance starting with PowerShell 3.0, but the documented brightness sample still uses the older command. The WMI namespace is Rootwmi , and the relevant class is WmiMonitorBrightnessMethods . If the command reports no compatible class or does not change the screen, use the display’s hardware controls or the normal Windows settings. WMI cannot reliably control every internal panel and is not a general external-monitor brightness interface. Use Night light for warmer colors Night light is not the normal screen-brightness control. It shifts the display toward warmer colors and reduces blue-light output. Its Strength value controls the color filter, not the display’s backlight brightness. Open Start > Settings > System > Display . Turn on Night light . To change the color effect, select Night light and move the Strength slider. To schedule it, open System > Display > Night light , turn on Schedule night light , and choose either Sunset to sunrise or Set hours . Outdated Drivers Are Slowing You Down PC Slower Than It Used to Be? If Night light is unavailable or grayed out, the display driver may not support it. Microsoft specifically notes issues with drivers such as DisplayLink or Basic Display ; updating the display driver is the recommended first step. Fix a missing or nonworking brightness slider For a non-desktop Windows 10 PC with a missing or nonworking brightness slider, Microsoft’s documented driver path is: Search the taskbar for Device Manager and open it. Expand Display adapters . Right-click the display adapter, or press and hold it on a touchscreen device. Select Update driver and follow the prompts. Also check whether an external display is selected as the active screen. If so, Windows may be controlling the built-in panel while the external monitor requires its own menu, or vice versa. Which brightness method should you use? Why is there no brightness slider in Windows 11? The most common reason is that the PC uses an external monitor. Windows may not provide a brightness slider for that display, so use the monitor’s physical buttons or joystick. On a laptop, update the display adapter driver through Device Manager and restart the PC. What is the difference between Windows brightness and Night light? Brightness changes the display’s light level. Night light applies a warmer color filter and includes a separate Strength control. Increasing Night light Strength does not replace the standard brightness slider. How do I stop Windows 11 from changing brightness automatically? Go to Start > Settings > System > Display > Brightness. Turn off “brightness automatically when lighting changes” if the PC offers that option. Also set “Change brightness based on content” to Off if brightness or contrast changes when webpages, videos, or other content changes. Can PowerShell change the brightness of an external monitor? The WMI WmiSetBrightness method works only with compatible displays and is not a universal external-monitor solution. If it fails, use the monitor’s built-in controls or a monitor-specific control utility supplied by its manufacturer. The Bottom Line For Windows 11, select the taskbar’s Network icon and move the Brightness slider, or use Start > Settings > System > Display . Windows 10 uses the Action center slider on version 1903 and later. If the computer uses a separate monitor, adjust brightness on the monitor itself. Disable the relevant adaptive-brightness option when Windows changes the level unexpectedly, and use Night light only when you want warmer colors rather than a simple brightness change. Recommended Free Tools Crashes, No Sound, or Screen Glitches? Windows Errors? 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