Find the brightness controls on your monitor
Most monitors have physical buttons on the front or side that control brightness. Look for buttons labeled with a sun icon, a plus and minus symbol, or words like "Menu" and "+" or "−". These are usually located on the bottom bezel (the frame below the screen) or along the side of the monitor frame.
Some monitors hide the buttons under a small panel or lip at the bottom. Run your finger along the bottom edge of the monitor to feel for raised buttons or a recessed area. If you cannot find physical buttons, your monitor may be controlled entirely through your computer's operating system or graphics card settings instead.
Check your monitor's manual if you own the box or documentation — it will show you exactly where the buttons are and what each one does. If you no longer have the manual, search online for your monitor's model number (usually printed on the back or bottom of the unit) plus "brightness controls" or "user manual".
Key Takeaways
- Most monitors have physical brightness buttons on the front or bottom edge, usually marked with a sun icon or plus and minus symbols.
- If your monitor has no physical buttons, you can adjust brightness through Windows Settings, macOS System Settings, or your graphics card control panel.
- On Windows, go to Settings > System > Display and use the brightness slider; on Mac, use System Settings > Displays.
- Some monitors also have an on-screen menu (accessed by pressing a Menu button) where you can fine-tune brightness and contrast separately.
Use the physical buttons to adjust brightness
Press the brightness button (usually marked with a sun icon) or the Menu button to open the monitor's on-screen display. Once the menu appears on your screen, use the plus and minus buttons to increase or decrease brightness. The change happens in real time, so you will see the screen get brighter or darker as you adjust.
If you see a menu with multiple options (contrast, color, input source, and so on), look for an option labeled "Brightness" or a sun icon. Select it and then use the plus or minus buttons to change the value. Exit the menu by pressing the Menu button again or waiting a few seconds — most monitors close the menu automatically.
Write down the brightness level you prefer, or take a photo of the on-screen menu showing your settings. If you ever need to reset the monitor, you will know what number to return to.
Adjust brightness through Windows Settings
On Windows 10 and Windows 11, open Settings by pressing the Windows key and typing "Settings", then click the app that appears. Go to System, then Display. You will see a brightness slider near the top of the screen — drag it left to dim the screen or right to brighten it.
If the slider is grayed out or missing, your graphics card or monitor may not support software brightness control. In that case, use the physical buttons on your monitor instead. Some laptops also have keyboard shortcuts for brightness: look for a sun icon on your function keys (F1 through F12) and press Fn plus that key to adjust.
Windows also has a "Night light" feature in the same Display settings that reduces blue light in the evening, which can make the screen easier on your eyes. This is separate from brightness but works alongside it — you can dim the screen and enable Night light at the same time.
Adjust brightness on a Mac
On macOS, click the Apple menu in the top left corner and select System Settings (or System Preferences on older versions). Click Displays, then drag the brightness slider left or right. The change takes effect when ready.
If you have a MacBook, you can also use the keyboard shortcut: press the brightness keys on your keyboard (usually F1 and F2, or keys with a sun icon). On an external monitor connected to a Mac, use the physical buttons on the monitor itself — macOS does not always control external displays through software.
Mac also has a "Night Shift" feature in Display settings that warms the screen color in the evening. Like Windows Night light, this works alongside brightness adjustment and can reduce eye strain during late-night work.
Use your graphics card control panel
If your monitor has no physical buttons and the operating system brightness slider does not work, your graphics card may have its own control panel. On Windows with an NVIDIA graphics card, right-click on the desktop and select NVIDIA Control Panel. Look for an option like "Adjust Desktop Color Settings" or "Brightness/Contrast" and use the sliders there.
For AMD graphics cards on Windows, right-click the desktop and select AMD Radeon Settings (or AMD Radeon Software). Navigate to Display settings and look for brightness or color controls. For Intel integrated graphics, right-click the desktop and select Intel Graphics Settings, then look for Display settings.
On a Mac with an external monitor, the graphics card control panel usually does not explore — use the monitor's physical buttons instead. If you are unsure which graphics card your computer has, check Device Manager on Windows (search "Device Manager" in Settings) under Display adapters, or on Mac, click the Apple menu and select About This Mac, then look under Graphics.
Troubleshoot brightness that will not change
If brightness controls do not work, first check whether your monitor is in power-saving mode. Some monitors dim automatically when they detect no input for several minutes. Move your mouse or press a key to wake the monitor, then try adjusting brightness again.
Next, make sure the monitor is receiving power and that the cable connecting it to your computer is fully plugged in on both ends. A loose cable can cause the monitor to ignore brightness commands. If the monitor is connected through a docking station or USB hub, try connecting it directly to your computer instead.
If you are using an external monitor on a Mac, the brightness controls may only work through the monitor's physical buttons, not through macOS settings. Check your monitor's manual to confirm whether it supports software brightness control. On Windows, update your graphics card drivers: search "Device Manager" in Settings, find your graphics card under Display adapters, right-click it, and select "Update driver".
Adjust contrast and other display settings
Brightness and contrast are different: brightness controls how light or dark the entire screen is, while contrast controls the difference between the lightest and darkest parts of the image. Most monitors let you adjust both through the same on-screen menu. Press the Menu button, find Contrast, and use the plus and minus buttons to change it.
You can also adjust color temperature (how warm or cool the screen looks), sharpness, and input source through the monitor menu. Experiment with these settings to find what feels comfortable for your eyes during long work sessions. If you make a mistake, most monitors have a "Reset" option in the menu that returns all settings to factory defaults.
For color-critical work like photo editing or video production, you may want to leave contrast and color settings at their defaults and only adjust brightness. Changing contrast or color can make your work look different on other screens, which causes problems when you share files with others.
Frequently Asked Questions
Why does my monitor brightness keep changing on its own?
Some monitors have an auto-brightness feature that adjusts the screen based on ambient light in the room. Check your monitor's on-screen menu for an option like "Auto Brightness" or "Adaptive Brightness" and turn it off if you prefer manual control. On Windows, check Settings > System > Display for an "Adaptive brightness" toggle and disable it if it is on.
Can I set different brightness levels for different programs?
No — brightness is a monitor-wide setting that applies to everything on screen at once. However, some programs (like photo editors or video players) have their own contrast and color controls that only affect that program's window. If you need different brightness for different tasks, you will need to manually adjust the monitor each time you switch.
What brightness level should I use?
Set brightness so that the screen is comfortable to look at for long periods without causing eye strain. A good starting point is around 50 to 75 percent brightness in a normally lit room. In a dark room, lower brightness to 25 to 50 percent to avoid eye fatigue. Adjust based on your preference — there is no single "correct" level.
Does lowering brightness save power?
Yes, slightly. Lowering brightness reduces the power the monitor uses, which can extend battery life on a laptop by a few percent. The savings are modest compared to other power-saving measures like closing unused programs or reducing screen refresh rate, but every bit helps on battery power.
Why is my monitor brightness slider grayed out in Windows?
This usually means your graphics card drivers are outdated or missing. Update your drivers by opening Device Manager (search in Settings), finding your graphics card under Display adapters, right-clicking it, and selecting "Update driver". If that does not work, use your monitor's physical buttons instead — they will always work regardless of driver status.