If you use a Dell monitor with a Windows 10 desktop or a laptop, you may have noticed that the brightness slider in Windows doesn’t change it, or doesn’t appear at all. That’s because Windows 10 can only control the brightness of built-in laptop screens directly; external monitors are adjusted with their own buttons or with software that talks to the monitor over its cable. This guide covers the monitor’s on-screen menu, Dell’s own software, free apps that add a brightness slider for external screens, and fixes when nothing works.
Quick Answer
Press one of the buttons on the bottom edge or back of the Dell monitor to open the menu, choose Brightness/Contrast, and use the up and down buttons (or the joystick) to set Brightness. To control it from Windows instead, install Dell Display Manager (called Dell Display and Peripheral Manager on newer models) from Dell’s support site.
Method 1: Use the Monitor’s Buttons
- Find the control buttons, usually under the bottom-right edge of the screen, or a small joystick on the back.
- Press any button (or the joystick) to show the shortcut menu, then choose the Menu icon.
- Select Brightness/Contrast.
- Choose Brightness and press up or down to change it. Many Dell monitors show the level from 0 to 100.
- Press the back or exit button to close the menu. The setting is saved automatically.
On many Dell models, one of the shortcut buttons is set to Brightness/Contrast by default, so a single press opens the slider. You can change shortcut keys under Menu > Personalize.
Method 2: Dell Display Manager (Control From Windows)
- Go to Dell’s support website, enter your monitor’s model or service tag, and download Dell Display Manager or Dell Display and Peripheral Manager, whichever is listed for your model.
- Install and open it. The app appears in the notification area.
- Click the icon and drag the Brightness slider. You can also set presets, auto mode per app, and window layouts.
This software works over DDC/CI, so that option must be turned on in the monitor’s menu (usually Menu > Others > DDC/CI > On).
Method 3: Free Apps for Any External Monitor
Free tools such as Twinkle Tray and Monitorian (both in the Microsoft Store) add a brightness slider for each connected monitor to the taskbar, like the one on laptops. They also use DDC/CI and work with most Dell and other brand monitors. Some support hotkeys and scheduled brightness changes.
Brightness Settings in Windows 10
- Laptop screens: use Settings > System > Display > Change brightness, the brightness tile in Action Center, or the laptop’s brightness keys. These don’t affect the external Dell monitor.
- Night light: Settings > System > Display > Night light warms the colors on all screens, including external ones, which can make a bright monitor more comfortable at night. It doesn’t change brightness itself.
- Windows 11: recent Windows 11 versions can show a brightness slider for some external monitors that support it, but Windows 10 can’t.
Brightness Won’t Change? Try These Fixes
- Grayed-out option: some preset modes, such as Dynamic Contrast or certain game or movie modes, lock brightness. Switch Preset Modes to Standard (under Color).
- HDR is on: in HDR mode, brightness may be controlled by Windows instead; turn off Use HDR in Display settings or use the SDR content brightness slider.
- Software slider doesn’t work: turn on DDC/CI in the monitor menu, use a direct DisplayPort or HDMI cable (some docks and adapters block DDC/CI), and update the graphics driver.
- Menu buttons locked: many Dell monitors lock the menu if you hold a button for about 10 seconds. Hold the same button again for 10 seconds to unlock it (check your model’s manual).
- Screen still too dim: reset the monitor to factory settings under Others > Factory Reset, then adjust again.
Frequently Asked Questions
What brightness level should I use?
Match the monitor to your room: dimmer in a dark room, brighter in daylight. Many people find 40–60% comfortable indoors, and lower brightness also reduces eye strain.
Can I use keyboard shortcuts for an external monitor?
Not by default. Twinkle Tray and similar apps let you assign hotkeys.
Does adjusting brightness affect color accuracy?
Slightly. For photo work, calibrate the monitor at the brightness you normally use.
Do these steps work with other brands?
Yes. Other monitors have similar on-screen menus, and the free apps work with most DDC/CI monitors.
Summary
- Press a button on the monitor and open Brightness/Contrast.
- Adjust Brightness with the up and down buttons.
- For a Windows slider, install Dell Display Manager or a free app like Twinkle Tray.
- Turn on DDC/CI if software control doesn’t work.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.