The fastest way to change brightness

On most Windows 10 laptops, you can adjust brightness using keyboard shortcuts. Look for brightness keys on your keyboard — usually on the function row (F1 through F12) with a sun icon. Hold the Fn key and press the brightness key to raise or lower the screen. The brightness key with a darker sun lowers brightness; the one with a brighter sun raises it.

If your keyboard doesn't have brightness keys, or if you prefer using your mouse, Windows 10 has a built-in brightness slider in the Quick Settings menu. Press Windows key + A to open Quick Settings, then drag the brightness slider left to dim or right to brighten.

Desktop monitors connected to a Windows 10 computer typically have physical buttons on the monitor itself for brightness control, not keyboard shortcuts. Look for buttons on the front or side of your monitor, usually marked with a sun icon or labeled "Menu".

Key Takeaways

  • Laptops usually have Fn + brightness key shortcuts, while desktops use physical buttons on the monitor itself.
  • Windows 10's Quick Settings menu (Windows key + A) has a brightness slider that works on any device.
  • If Quick Settings doesn't show a brightness slider, your device may not have a compatible brightness sensor or driver.
  • The Settings app offers more detailed brightness control, including automatic brightness adjustment based on ambient light.

Using the Settings app for more control

For additional brightness options beyond the Quick Settings slider, open the Settings app by pressing Windows key + I. Go to System, then select Display from the left menu.

Under the Display settings, you'll see a brightness slider near the top. Drag it to adjust brightness manually. Below that, you may see a toggle for Change brightness automatically when lighting changes — this uses your device's ambient light sensor to adjust brightness based on your surroundings. If you have this option, turning it on can reduce eye strain in different lighting conditions.

Some Windows 10 devices also show a Night light option in Display settings. This reduces blue light in the evening, which some people find easier on their eyes before bed. You can set it to turn on automatically at a specific time or keep it on all day.

When brightness keys don't work

If your keyboard's brightness keys don't respond, the issue is usually a missing or outdated driver. Drivers are software that let Windows communicate with your hardware. To check for driver updates, right-click the Start button and select Device Manager.

Look for Monitors or Display adapters in the list. Right-click on your display device and select Update driver. Choose Search automatically for updated driver software and let Windows search for the latest version. If an update is found, install it and restart your computer.

If updating the driver doesn't help, the brightness keys may be controlled by your laptop manufacturer's own software. Check your laptop maker's website (Dell, HP, Lenovo, etc.) for a control panel or utility program specific to your model. Some manufacturers bundle brightness control into a separate app rather than using Windows' built-in system.

Brightness control for external monitors

If you're using an external monitor connected to a Windows 10 desktop or laptop, brightness is controlled through the monitor's physical buttons, not through Windows. Most monitors have buttons on the front bezel or along the bottom edge. Press the menu button (usually in the center or marked with three horizontal lines) to open the on-screen menu.

Navigate to Brightness or Contrast using the arrow buttons, then adjust with the plus or minus buttons. The exact menu layout varies by monitor brand — Dell, LG, ASUS, and others arrange their menus differently. If you can't find the brightness control, check your monitor's manual or the manufacturer's website for your specific model number.

Some newer monitors support USB or wireless control from your computer, but this requires special software from the monitor maker. Most standard monitors rely only on physical buttons.

Troubleshooting when nothing works

If the Quick Settings slider is missing or grayed out, your device may not have a brightness sensor, or the sensor driver isn't installed. Try the Device Manager update described above, focusing on any devices listed under Human Interface Devices that mention "brightness" or "ambient light".

On some older or budget laptops, brightness control may not be available at all through Windows — the hardware simply doesn't support it. In that case, you're limited to adjusting brightness through your monitor's physical buttons if it's external, or you may need to adjust display settings like contrast or gamma as a workaround.

If you've tried updating drivers and the brightness slider still doesn't appear, restart your computer. Sometimes Windows needs a restart to recognize new drivers or re-enable hardware features that were previously disabled.

Using third-party brightness tools

If Windows' built-in brightness control isn't working and you can't update drivers, some people use third-party software to adjust screen brightness. Programs like f.lux or Dimmer can lower brightness and adjust color temperature, though they work differently than hardware brightness control — they're actually changing what's displayed on screen rather than adjusting the backlight.

These tools are useful for reducing eye strain or saving battery life, but they're not a replacement for actual hardware brightness adjustment. They also use more CPU power than native brightness control, which can slightly reduce battery life on laptops despite appearing to dim the screen.

Frequently Asked Questions

Why does my brightness slider disappear after I restart?

This usually means the brightness driver didn't install correctly or was disabled. Open Device Manager, look for your display device under Monitors or Display adapters, right-click it, and select Update driver. If that doesn't work, check your laptop manufacturer's website for a brightness control utility specific to your model.

Can I set brightness to turn on automatically at different times?

Windows 10 doesn't have a built-in schedule for brightness changes, but the automatic brightness feature (if your device has it) adjusts based on ambient light in your room. For scheduled changes, you'd need third-party software like f.lux, which can dim your screen at a set time each evening.

Does lowering brightness save battery on a laptop?

Yes. The screen is one of the largest power consumers on a laptop. Lowering brightness, especially the backlight brightness controlled through hardware, can noticeably extend battery life. Automatic brightness adjustment can help balance visibility and battery use throughout the day.

What if my external monitor has no menu button?

Some monitors use touch-sensitive controls instead of physical buttons, usually along the bottom edge. Look for a small icon or marking. If you still can't find controls, check your monitor's model number (usually on the back) and search the manufacturer's website for the manual, which will show you exactly where the controls are.