To adjust display brightness in Windows 11, open Quick Settings (press Windows logo key + A, or select the Network icon on the taskbar) and drag the Brightness slider, or go to Settings > System > Display and use Brightness. In Windows 10, use the Brightness slider in action center. External monitors usually need their own buttons or a DDC/CI app such as PowerToys Power Display, Monitorian, Twinkle Tray or MonitorPilot.
This guide covers every built-in method, automatic brightness, why the slider sometimes disappears, and an honest comparison of the apps that can dim an external monitor.
How do I change brightness in Windows 11?
Microsoft lists two manual routes on its display brightness and color page:
- Select the Network icon on the right side of the taskbar, then move the Brightness slider.
- Or open Start > Settings > System > Display and adjust Brightness.
The keyboard route is Windows logo key + A, which Microsoft’s keyboard shortcuts list describes as opening the Windows 11 action center (Quick Settings). Most laptops also have dedicated brightness keys, often used together with the Fn key. Those keys are set by the manufacturer, so check your laptop’s documentation if they do nothing.
How do I change brightness in Windows 10?
On Windows 10, version 1903 and later:
- Select action center on the right side of the taskbar.
- Move the Brightness slider.
On earlier Windows 10 versions, Microsoft says to go to Settings > System > Display and move the Change brightness slider. Note that Windows 10 support ended on October 14, 2025, so Microsoft recommends moving to Windows 11.
Every way to change brightness, side by side
| Method | Windows 11 | Windows 10 | Laptop screen | External monitor |
|---|---|---|---|---|
| Quick Settings or action center slider | Network icon or Win+A | Action center (1903 and later) | Yes | Usually no |
| Settings | System > Display > Brightness | System > Display | Yes | Usually no |
| Laptop brightness keys | Manufacturer keys | Manufacturer keys | Yes | No |
| Automatic (light sensor) | Brightness > Change brightness automatically when lighting changes | Brightness and color check box | Yes, with a sensor | No |
| Monitor buttons (OSD menu) | Physical buttons | Physical buttons | No | Yes |
| DDC/CI app | Third-party or PowerToys | Third-party or PowerToys | Depends on the app | Yes, if DDC/CI is on |
How do I make Windows adjust brightness automatically?
Windows has two automatic features, and both only apply to a built-in screen.
Based on lighting. Some PCs have an ambient light sensor. On Windows 11, go to Start > Settings > System > Display, select Brightness and turn on Change brightness automatically when lighting changes. On Windows 10, go to Settings > System > Display and, under Brightness and color, select the Change brightness automatically when lighting changes check box. If you do not see the option, your PC most likely has no light sensor. You can still fine-tune with the slider while it is on.
Based on content. Some Windows 11 PCs can change brightness and contrast based on what is on the built-in screen. Go to Settings > System > Display > Brightness and set Change brightness based on content to:
- Off: brightness and contrast are not adjusted, which can mean shorter battery life.
- Always: runs whether the device is plugged in or on battery.
- On Battery Only: runs only on battery power.
Microsoft notes that if these sudden changes are distracting, or you work in photo and video apps where color accuracy matters, you can turn this off. Its energy recommendations page also states that the screen brightness recommendation is not yet enabled for external displays.
Why is the brightness slider missing?
Microsoft puts it plainly: “You might not see the Brightness slider on devices that have an external monitor. To change the brightness on an external monitor, use the buttons on it.”
The common causes:
- Desktop PC with an external monitor. Windows does not send brightness commands to most external displays, so there is no slider. This is normal.
- Laptop with a display driver problem. If you are on a laptop and the slider does not appear or work, Microsoft suggests updating the display driver: search for Device Manager, expand Display adapters, right-click the adapter and select Update driver.
- Brightness changing on its own. That is a different problem, usually adaptive brightness or a power setting. Our guide to monitor brightness that keeps changing by itself walks through each cause.
For the longer technical story, see why Windows 11 can’t control external monitor brightness.
How do I change brightness on an external monitor?
There are two routes:
- The monitor’s own buttons. This is what Microsoft recommends, and it always works.
- DDC/CI. Most modern monitors accept brightness, contrast and input commands from the PC over the video cable through a standard called DDC/CI. Some ship with it turned off, so you may need to enable it in the monitor’s on-screen menu. Once it is on, an app can change brightness from the taskbar instead of the bezel.
If an app cannot see your monitor, our DDC/CI not working on Windows 11 guide covers cables, docks and monitor settings. On HDR displays, note that the SDR content brightness slider in Windows is not the same as the monitor’s backlight; see SDR content brightness vs monitor brightness.
Which external monitor brightness app should I use?
All four tools below talk to monitors over DDC/CI. They differ in price, Windows versions and whether they also handle a laptop’s built-in screen.
| Tool | Price | Windows | Laptop screen | External DDC/CI | Automation | Worth knowing |
|---|---|---|---|---|---|---|
| Windows built-in | Free | 11 and 10 | Yes | No | Light sensor and content-based, built-in screen only | Microsoft says to use the monitor’s buttons |
| PowerToys Power Display | Free | Where PowerToys runs | Detected separately | Yes: brightness, contrast, volume, input, rotation, color temperature, power | Profiles, linked brightness | Microsoft warns some monitors can trigger a system crash during capability reads |
| Monitorian | Free; Store add-ons for hot keys and command-line options are on a subscription basis | Windows 7 and later (Store version: Windows 10 1607 or later) | Yes | Yes, brightness and contrast | Individual or unison control | Minimal tray slider |
| Twinkle Tray | Free | 10 and 11 | Most laptops | Yes, plus contrast, volume and power | Brightness by time of day or when idle | Covers laptop and monitors in one slider |
| MonitorPilot | $12.99 in the Microsoft Store | 11 only | No | Yes: brightness, contrast, input, volume, color temperature, power | Per-app rules, conditional rules, sunrise to sunset curve, profiles, sync groups | Offline, no account |
A fair verdict:
- One monitor, occasional changes: the monitor’s buttons or a free app is enough. Monitorian or Twinkle Tray give you a tray slider, and Power Display makes sense if you already run PowerToys.
- A laptop plus monitors on one slider: Twinkle Tray covers laptop screens too. MonitorPilot does not.
- Windows 10: MonitorPilot is not an option because it is Windows 11 only. Monitorian, Twinkle Tray and PowerToys are.
- Rules that run themselves: Twinkle Tray already does time-of-day brightness for free. MonitorPilot is worth paying for if you want per-app rules (dim when a video player is in focus, brighten for a design app), layered conditions and a sunrise to sunset curve together in one offline app on Windows 11.
We compare two of these head to head in Monitorian vs MonitorPilot, and if your two screens never look the same, see how to match brightness on two monitors.
Per-app brightness rules and a sunrise to sunset curve for external DDC/CI monitors on Windows 11. It cannot dim a laptop’s built-in screen.
Get it from Microsoft
How does MonitorPilot fit in?
According to its Microsoft Store listing, MonitorPilot lives in the system tray and controls DDC/CI-capable external displays:
- Hardware controls: brightness, contrast, input source, volume, color temperature and power.
- Profiles: named setups such as Work or Night, applied in one click.
- Per-app automation: apply a profile or brightness level when a specific app comes into focus.
- Location-aware schedules: clock time or local sunrise and sunset, computed on the device with no network.
- Sync groups: move several monitors together with per-monitor offsets.
- Hotkeys and tray scroll: nudge brightness without opening a window.
The listing is direct about limits: “Laptop built-in panels generally do not expose DDC/CI and cannot be controlled this way,” and the app is Windows 11 only. For a laptop screen, use the Windows slider.
Frequently asked questions
How do I change the brightness on an external monitor?
Use the buttons on the monitor, which is Microsoft’s own advice. If the monitor supports DDC/CI and it is enabled in its menu, a DDC/CI app can change brightness from Windows instead.
How do I change brightness on an external monitor without buttons?
Turn on DDC/CI in the monitor’s on-screen menu, then use a DDC/CI app: PowerToys Power Display, Monitorian, Twinkle Tray, or MonitorPilot on Windows 11. If none of them sees the monitor, the cable, dock or adapter may not pass DDC/CI.
How do I turn on adaptive brightness in Windows 11?
Go to Settings > System > Display > Brightness and turn on Change brightness automatically when lighting changes. It needs an ambient light sensor, so most desktops and external monitors will not show it.
Why is adaptive brightness missing in Windows 11?
The usual reason is that the PC has no light sensor, or you are using an external monitor, which Windows does not adjust automatically. On a laptop, an outdated display driver can also hide brightness options.
What is the best app for adjusting brightness?
For most people a free tool is enough: Twinkle Tray if you want laptop and monitor control together, Monitorian for a simple slider, or PowerToys Power Display if you already use PowerToys. MonitorPilot suits Windows 11 users who want per-app and schedule-based rules for external monitors.
How do I stop screen brightness from adjusting itself?
Turn off Change brightness automatically when lighting changes and set Change brightness based on content to Off. If it still changes, follow our guide to brightness that keeps changing by itself.
Try MonitorPilot
MonitorPilot is in the Microsoft Store for Windows 11 and external monitors with DDC/CI. More detail is on the MonitorPilot product page.
Control external monitor brightness from the tray on Windows 11, with rules that run on their own.
Get it from Microsoft
Windows and PowerToys are trademarks of the Microsoft group of companies. MonitorPilot is not affiliated with or endorsed by Microsoft. Monitorian and Twinkle Tray are independent projects of their respective developers.
Last updated 23 October 2026. Published by Automata Labs, a software company in Canada.