You’re in a dark room. Your screen is too bright. You press the brightness down key… and nothing happens. Uh-oh. Don’t worry — it’s a common problem and we’re going to solve it together. This guide is for any laptop user whose brightness function key isn’t working. Whether you’re using Windows, macOS, or even Linux — we’ve got tips and tricks to bring back your glow control.
Why Did the Brightness Key Stop Working?
Before we jump into fixes, let’s quickly figure out what might be causing the issue.
- Driver issues – Your display or keyboard drivers might be outdated or corrupted.
- Disabled services – Some Windows services control brightness settings.
- Function key lock – Some laptops have a setting that disables the function keys.
- Broken keyboard – That specific key might actually be busted.
Let’s fix it! 🔧
Method 1: Use the Brightness Slider
This is the easiest workaround!
On Windows:
- Click the Start menu.
- Go to Settings > System > Display.
- Under “Brightness and Color,” drag the Change brightness slider left or right.
Still can’t move the slider? Time for some deeper digging.
Method 2: Update Your Display Drivers
Corrupt or outdated drivers are a common culprit.
- Right-click the Start menu.
- Select Device Manager.
- Expand the Display adapters section.
- Right-click your graphics driver and choose Update driver.
- Select Search automatically for drivers.
If that doesn’t work, try downloading the latest driver from the laptop manufacturer’s website.
Method 3: Check the Keyboard Driver
If the brightness key isn’t working, maybe the keyboard driver is misbehaving.
- Open Device Manager.
- Go to Keyboards.
- Right-click your keyboard and select Update driver.
Still nothing? You can also uninstall it, then restart your computer — Windows will reinstall it on boot.
Method 4: Use Software Control Tools
Third-party apps can give you fine-tuned control over brightness. They work even if your keys don’t!
- f.lux – Adjusts screen brightness automatically based on time of day.
- Windows Brightness Slider – A simple tray icon with a brightness slider.
- Iris – Offers health-focused lighting and brightness features.
Install one of these and keep your eyes comfy.
Method 5: Check Windows Mobility Center
This tool gives you quick access to brightness settings.
- Right-click the battery icon in the system tray.
- Select Windows Mobility Center.
- Use the brightness slider inside the window.
Tip: If the brightness option is grayed out, it might mean Windows can’t detect your display properly.
Method 6: Tweak Your Power Plan Settings
Some power plans adjust brightness automatically—or disable brightness control!
- Open Control Panel.
- Click Hardware and Sound.
- Select Power Options.
- Next to your active plan, click Change plan settings.
- Edit brightness behavior under “On battery” or “Plugged in”.
Method 7: BIOS and Function Key Settings
Many laptops have a Function Lock. If it’s turned on, the brightness shortcut won’t work unless you also hold the Fn key every time.
Try this sequence:
- Restart your laptop.
- Hit the BIOS access key. Usually F2, DEL, or ESC.
- Look for Function Key Behavior settings.
- Change it from Multimedia to Function (or the other way).
Method 8: Roll Back or Reinstall Windows Updates
Sometimes, a recent update is the troublemaker. If brightness stopped working after an update, consider rolling it back.
- Open Settings.
- Go to Update & Security > Windows Update.
- Click View update history.
- Select Uninstall updates.
- Choose the one causing issues and uninstall it.
Warning: Only do this if you’re sure the update is the cause.
Still Not Working?
If all else fails, here are some last ideas:
- External keyboard – Plug one in and test the brightness keys there.
- Hardware test – Your laptop might have a built-in diagnostic tool.
- Factory reset – As a last resort, reset the system (don’t forget to back up!).
For Mac Users 🍏
If you’re on a Mac and brightness keys aren’t working:
- Click the Apple menu > System Settings.
- Choose Displays.
- Uncheck Automatically adjust brightness and try adjusting manually.
- Restart your Mac.
If that doesn’t help, try resetting NVRAM:
- Shut down the Mac.
- Turn it on and immediately press and hold: Option + Command + P + R.
- Hold for about 20 seconds, then release.
Keep It Bright, Keep It Right
Brightness control is a vital feature — not just for comfort but for battery life too! If your function key isn’t working, one of these fixes will surely get it back in shape. Most cases are driver-related, so updating your display and keyboard software is usually the golden ticket. If not, there are plenty of nifty workarounds and tools to help.
So go ahead — tweak that screen until it’s just right. Your eyes will thank you. 😎