Adjust brightness using your keyboard or operating system

The fastest way to brighten your screen is usually through your keyboard. Most laptops have dedicated brightness keys—look for sun symbols on the function row (F1 through F12). Hold Fn and press the brightness-up key, typically on the right side of that row. On Windows desktops without these keys, go to Settings > System > Display and drag the brightness slider to the right. On Mac, click the Control Center in the top-right corner, find Display, and adjust the slider there.

If your keyboard keys don't work, your laptop may have a separate brightness control in the system settings. Windows users can also right-click the desktop, select Display settings, and look for a brightness control near the top of the window. The exact location varies by Windows version, but it's always under Display settings somewhere.

Key Takeaways

  • Keyboard function keys (Fn + brightness key) are the quickest method on most laptops and work when ready without opening menus.
  • Windows and Mac both offer brightness sliders in their display settings if keyboard shortcuts don't work or aren't available.
  • External monitors have physical buttons or dials on the back or bottom that control brightness independently of your computer.
  • If brightness controls are grayed out or missing, your graphics driver may need updating through Device Manager (Windows) or Software Update (Mac).
  • Extremely dim screens can sometimes signal a hardware problem, and if no control method works, the monitor or laptop display may need professional service.

Adjust brightness on an external monitor

External monitors have their own brightness controls separate from your computer's settings. Look for physical buttons or a dial on the back, bottom, or side of the monitor. Press the button labeled with a sun symbol or a plus sign, or use the menu button to access an on-screen display (OSD) where you can find brightness. Some monitors also include a small remote control in the box.

If your monitor has an OSD menu, you'll usually navigate it with arrow buttons and confirm selections with a center button. Brightness is almost always the first or second option in that menu. Once you've adjusted it, the change takes effect when ready on that monitor only—it won't affect your laptop screen or other displays.

Update your graphics driver

If brightness controls are grayed out, missing, or not responding, your graphics driver may be outdated or corrupted. On Windows, right-click the Start button, select Device Manager, and expand Display adapters. Right-click your graphics card (usually Intel, NVIDIA, or AMD) and select Update driver. Choose Search automatically for updated driver software and let Windows find and install the latest version.

On Mac, go to the Apple menu, select System Settings (or System Preferences on older versions), then General > Software Update. Mac handles graphics drivers as part of system updates, so this will catch any needed updates. After updating, restart your computer and try the brightness controls again.

Check for power-saving or battery modes

Some laptops automatically dim the screen when running on battery power to save energy. If your screen seems stuck at a low brightness, check whether your laptop is in battery saver mode or power-saving mode. On Windows, click the battery icon in the system tray (bottom-right corner) and look for a power mode slider. Switch it from Battery saver or Best battery life to Balanced or Best performance.

On Mac, go to System Settings > Battery and check whether Low Power Mode is turned on. Turn it off if brightness is your priority. You can also disable automatic brightness adjustment in the same menu—look for an option like Automatically adjust brightness and uncheck it if you want manual control.

Disable automatic brightness adjustment

Many modern laptops adjust brightness automatically based on ambient light using a built-in sensor. This can make the screen feel dimmer than you want. On Windows, go to Settings > System > Display and scroll down to find Brightness and color. Look for a toggle labeled Change brightness automatically or Adaptive brightness and turn it off.

On Mac, open System Settings > Displays and uncheck Automatically adjust brightness. Once disabled, your screen will stay at whatever brightness level you set manually. You can always turn automatic adjustment back on later if you prefer it.

Adjust display settings for better visibility

If your screen is bright but still hard to read, the problem may not be brightness alone. Check your contrast and color settings. On Windows, go to Settings > System > Display > Advanced display settings and look for color or contrast options. Some monitors also have contrast controls in their physical buttons or OSD menu.

You can also increase text size to reduce eye strain. On Windows, go to Settings > Accessibility > Display and adjust the text size slider. On Mac, go to System Settings > Accessibility > Display and increase the text size. These changes affect how content appears across your whole system, not just one process.

When to call for professional help

If you've tried all the steps above and your screen remains extremely dim, or if brightness controls don't appear anywhere in your settings, the problem may be hardware-related. A failing backlight (the light behind the screen), a damaged graphics card, or a broken monitor can't be fixed through software adjustments.

Contact the manufacturer of your laptop or monitor with the model number (usually on a sticker on the back). They can tell you whether repair or replacement is the right option. If your device is under warranty, the repair may be covered. For older devices, a technician can sometimes replace just the backlight or monitor panel rather than the whole unit, which costs less than a full replacement.

Frequently Asked Questions

Why does my screen get dimmer when I unplug my laptop?

Your laptop is likely in battery saver mode, which dims the screen to extend battery life. Check your power settings and switch to Balanced mode if you want the same brightness on battery. You can also disable automatic brightness adjustment so the screen stays at your chosen level whether plugged in or not.

Can I make my screen brighter than the maximum setting?

No—the maximum brightness setting is the limit of your display's backlight. If that's not bright enough, the issue is usually ambient light (sunlight or bright room lighting) washing out the screen. Try adjusting contrast, moving to a darker location, or using an anti-glare screen protector. Some external monitors are brighter than laptop screens, so that's an option if you work in very bright spaces.

My brightness keys work sometimes but not always—why?

This usually means your graphics driver is unstable or partially corrupted. Update your driver through Device Manager (Windows) or Software Update (Mac). If the problem persists after updating, try uninstalling the driver completely, restarting your computer, and letting the system reinstall it automatically.

Does brightness affect battery life?

Yes—a brighter screen uses more power. If you're on battery and want to extend your runtime, lowering brightness is one of the most effective steps you can take. Switching to battery saver mode also dims the screen automatically, which is why your laptop may feel dimmer when unplugged.

What if my external monitor has no brightness buttons?

Some older or very basic monitors don't have physical controls. In that case, you can only adjust brightness through your computer's display settings, which affects all connected displays together. If that's not enough, you may need to replace the monitor with one that has its own brightness controls.