The fastest way to change brightness on your computer

The quickest method depends on your operating system. On Windows 10 and 11, press the Windows key and the letter A together to open the Quick Settings panel, then drag the brightness slider left to dim or right to brighten. On a Mac, click the Control Center icon in the top-right corner and drag the brightness slider. On Linux, the method varies by desktop environment, but GNOME (the most common) uses the system menu in the top-right corner.

If your keyboard has brightness keys—usually marked with a sun icon and located on the function row—you can press them directly without opening any menu. On Windows laptops, these are often Fn + F2 (or F3, F4, F5, depending on your model). On Macs, use the brightness keys without holding Fn. This is the fastest option if your keyboard has them.

Key Takeaways

  • Windows 10 and 11 users can adjust brightness when ready using Windows key + A, then dragging the slider in Quick Settings.
  • Mac users should click Control Center in the top-right corner and use the brightness slider there.
  • Most laptop keyboards have dedicated brightness keys (marked with a sun symbol) that work when ready without opening menus.
  • Monitor brightness is separate from screen brightness and requires accessing your monitor's physical buttons or on-screen menu.
  • If brightness keys do not work, you may need to install or update graphics drivers on Windows or check keyboard settings on Mac.

Adjusting brightness in Windows 10 and 11

Open Quick Settings by pressing Windows key + A. A panel will slide in from the right side of your screen. Look for the brightness slider—it shows a sun icon and a horizontal bar. Drag the slider to the left to make your screen darker or to the right to make it brighter. The change happens when ready as you drag.

If you do not see a brightness slider in Quick Settings, your graphics driver may need updating. Go to Settings > System > Display > Advanced display settings, then scroll down and click "Graphics" to see your graphics card name. Visit the manufacturer's website (Intel, NVIDIA, or AMD), read the latest driver for your card, and install it. Restart your computer and try Quick Settings again.

For older Windows 10 machines, you can also adjust brightness through Settings > System > Display. Scroll down to find the brightness slider under "Brightness and color." This method is slower than Quick Settings but works on all Windows 10 versions.

Adjusting brightness on a Mac

Click the Control Center icon in the top-right corner of your menu bar—it looks like a rectangle with several small squares. A panel will open. Find the brightness slider, which shows a sun icon, and drag it left to dim or right to brighten. The change takes effect when ready.

If you do not see Control Center in your menu bar, go to System Settings > Control Center and make sure "Brightness" is toggled on. You can also choose whether brightness appears in the menu bar or only when you open Control Center.

On older Macs running earlier versions of macOS, use the brightness keys on your keyboard instead. Press the key with the sun and downward lines to dim, or the sun with upward lines to brighten. No menu is needed.

Using keyboard brightness keys

Most laptops have dedicated brightness keys on the keyboard. On Windows laptops, these are usually in the function row (the top row of keys) and marked with a sun icon. Press Fn + the brightness key to adjust. On some newer Windows laptops, you do not need to hold Fn—just press the brightness key alone.

On Macs, the brightness keys are also in the function row. Press the key with the sun and downward lines to dim, or the sun with upward lines to brighten. You do not need to hold any other key.

If your keyboard brightness keys do not work on Windows, the function keys may be locked. Look for a key marked "Fn Lock" or a key with an Fn symbol and a lock icon. Press it once to unlock function keys, then try the brightness keys again. If they still do not work, your graphics driver needs updating (see the Windows section above).

Adjusting monitor brightness separately from screen brightness

Your monitor has its own brightness setting, separate from your computer's screen brightness. If adjusting your computer's brightness does not make a noticeable difference, your monitor's brightness may be turned down very low.

Look for physical buttons on the front or bottom edge of your monitor. Usually there is a menu button (often marked with lines or a square) and up/down buttons. Press the menu button, then use the arrow buttons to navigate to "Brightness" or "Backlight." Use the up arrow to increase brightness or the down arrow to decrease it. Press menu again to exit.

If your monitor has no physical buttons, it may have an on-screen menu controlled by a joystick or touch-sensitive area. Check your monitor's manual or the manufacturer's website for instructions specific to your model.

Troubleshooting brightness that will not change

If your screen brightness does not change when you adjust the slider or press brightness keys, first check whether your monitor's brightness is already at maximum. Adjust the monitor's physical buttons as described above.

On Windows, open Device Manager by right-clicking the Start button and selecting "Device Manager." Look for "Display adapters" and click the arrow to expand it. Right-click your graphics card and select "Update driver." Choose "Search automatically for updated driver software." Windows will search online and install any available updates. Restart your computer and try adjusting brightness again.

On a Mac, brightness problems are rare, but if your screen will not dim or brighten, restart your computer. If the problem persists, go to System Settings > Displays and check whether "Auto-brightness" is turned on. If it is, turn it off and try adjusting manually. If brightness still does not work, restart in Safe Mode by holding Shift while restarting, then test brightness again.

On Linux, brightness adjustment depends on your desktop environment and graphics card. Open your terminal and type xrandr --output HDMI-1 --brightness 0.7 (replace HDMI-1 with your display name and 0.7 with a number between 0 and 1). Type xrandr alone to see your display name. If this works, you can create a keyboard shortcut in your system settings to run this command.

Adjusting brightness for eye comfort

Brightness that is too high can cause eye strain, especially in dim rooms. A good starting point is to set your brightness so that your screen is about as bright as the wall behind it. If you work in a dark room, lower your brightness further and consider enabling a blue light filter.

On Windows 10 and 11, you can enable "Night light" to reduce blue light in the evening. Open Settings > System > Display and toggle on "Night light." You can set a schedule so it turns on automatically at sunset. On a Mac, go to System Settings > Displays > Night Shift and turn it on. Both features make your screen warmer (more yellow, less blue) to reduce eye strain before bed.

Frequently Asked Questions

Why does my brightness slider not appear in Windows Quick Settings?

Your graphics driver is likely outdated or missing. Open Device Manager, expand "Display adapters," right-click your graphics card, and select "Update driver." Choose "Search automatically for updated driver software." After Windows installs the update, restart your computer and open Quick Settings again.

Can I set brightness to change automatically based on the time of day?

Yes. On Windows, open Settings > System > Display, scroll down, and toggle on "Night light." Click "Night light settings" to set a schedule. On a Mac, go to System Settings > Displays > Night Shift and turn it on, then set your preferred schedule. Both will gradually warm your screen in the evening and return to normal in the morning.

My laptop brightness keys work sometimes but not always. What is wrong?

Function keys may be locked. Look for a key marked "Fn Lock" or a key with an Fn symbol and a lock icon, usually in the function row. Press it once to toggle function key mode. If brightness keys still do not work, update your graphics driver on Windows or restart your Mac.

Is there a difference between screen brightness and monitor brightness?

Yes. Screen brightness is controlled by your computer's operating system and affects the display panel itself. Monitor brightness is a separate physical setting on your monitor's buttons or menu. If adjusting your computer's brightness does not help, try adjusting your monitor's brightness using its physical controls.

What brightness level is best for my eyes?

Set your screen brightness to match the brightness of your surroundings. In a bright room, use higher brightness. In a dim room, lower your brightness so your screen is not much brighter than the wall behind it. Enable Night light (Windows) or Night Shift (Mac) in the evening to reduce blue light and eye strain before bed.