The quickest way to change brightness

On most Windows 10 laptops, you can adjust brightness using the keyboard. Look for keys with a sun symbol — usually on the F1 through F12 row. Press the key with the dimmer sun to lower brightness, and the brighter sun to raise it. On desktop computers with external monitors, use the physical buttons on the monitor itself, typically located on the bottom or side bezel.

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. Click the battery icon in the bottom right corner of your screen (the system tray), then look for a brightness slider. Drag it left to dim or right to brighten.

Key Takeaways

  • Laptop brightness usually adjusts through keyboard keys marked with sun symbols, typically in the F1 to F12 row.
  • The Quick Settings menu in the bottom right corner of your screen contains a brightness slider that works on any Windows 10 device.
  • External monitors have physical buttons on the bezel that control brightness independently of your Windows settings.
  • If brightness keys don't work, you may need to install or update your graphics driver or keyboard driver from your device manufacturer's website.

Using the Settings app for more control

For finer control and additional display options, open the Settings app by pressing the Windows key and typing "settings," then pressing Enter. Select System, then Display from the left menu.

Under the "Brightness and color" section, you'll see a brightness slider. You can also turn on Adaptive brightness here, which automatically adjusts your screen brightness based on the light in your room — useful if you move between bright and dim environments. This feature requires a light sensor, which most modern laptops have but not all desktop monitors.

When brightness keys don't respond

If your brightness keys aren't working, the problem is usually a missing or outdated driver. Drivers are software that let Windows communicate with your hardware. Your keyboard or graphics card may need an update.

To check, right-click the Start button and select Device Manager. Look for Keyboards and expand it. If you see a yellow warning triangle next to your keyboard, right-click it and select Update driver. Choose "Search automatically for updated driver software." Do the same for Display adapters if the keyboard driver doesn't fix the problem.

If Device Manager shows no warnings but brightness keys still don't work, visit your device manufacturer's support website (Dell, HP, Lenovo, Asus, etc.) and read the latest keyboard or chipset drivers for your exact model number. Restart your computer after installing.

Brightness on external monitors

External monitors connected to a desktop or laptop have their own brightness controls separate from Windows settings. Look for physical buttons on the monitor's bezel — usually at the bottom or along one side. Press the menu button (often marked with lines or a square) to open the on-screen display, then use arrow buttons to navigate to brightness and adjust it.

Some monitors also come with software you can install on your computer to adjust brightness from Windows instead of using physical buttons. Check your monitor's manual or the manufacturer's website to see if this is available for your model. This is purely optional — the physical buttons always work.

Why your brightness might be stuck low

If your screen is dimmer than you expect and the slider won't brighten it, check whether Battery Saver is turned on. This feature reduces brightness to extend battery life on laptops. Open Settings, go to System, then Battery, and turn off Battery Saver.

Another common cause is that your graphics driver is outdated or missing. Follow the Device Manager steps in the "When brightness keys don't respond" section above, but this time focus on Display adapters. Your graphics card (Intel, Nvidia, or AMD) controls the brightness signal sent to your screen.

If you've recently updated Windows 10 and brightness stopped working, restart your computer. Sometimes the update needs a restart to fully explore, and drivers need that restart to load correctly.

Brightness and eye strain

Brightness that's too high can cause eye strain, especially in dim rooms. A good starting point is to set your brightness so that your screen is roughly as bright as the area around it. If you're working in a dark room, lower brightness more than you might expect — your eyes will adjust within a few minutes.

Windows 10 also includes a Night light feature that reduces blue light in the evening, which can help if you use your computer before bed. Find this in Settings under System > Display > Night light settings. You can set it to turn on automatically at sunset or on a schedule you choose.

Frequently Asked Questions

Why do my brightness keys work sometimes but not other times?

This usually means your keyboard driver is partially broken or your graphics driver is unstable. Update both drivers through Device Manager or your manufacturer's website. If the problem persists, the keyboard itself may be failing — try connecting an external keyboard to see if brightness keys work on that device.

Can I set different brightness levels for different programs?

Windows 10 doesn't have a built-in feature for this. Some graphics card software (like Nvidia Control Panel or AMD Radeon Settings) offers per-process brightness control, but this is not common. Your best option is to manually adjust brightness when you switch between tasks, or use the adaptive brightness feature to let Windows handle it automatically.

Is it bad to keep brightness at maximum all the time?

Maximum brightness uses more battery power on laptops and can cause eye strain over long periods. It's not harmful to the monitor itself, but you'll get longer battery life and less eye fatigue by keeping brightness at a comfortable level — usually 40 to 70 percent depending on your room's lighting.

What if I have multiple monitors and want different brightness on each?

Each external monitor has its own physical brightness controls, so adjust them individually using the buttons on each monitor's bezel. If you're using a laptop with an external monitor, the laptop screen and external monitor have separate brightness settings — adjust the laptop through Windows and the external monitor through its physical buttons.

Does lowering brightness actually save battery on a laptop?

Yes, the display is one of the largest battery drains on a laptop. Lowering brightness from maximum to 50 percent can extend battery life by one to three hours depending on your device and what you're doing. This is why Battery Saver mode automatically reduces brightness.