How to Turn Off Auto-Brightness on Windows 11

Stopping Windows from Dimming Your Screen

Modern laptops and premium desktop monitors are equipped with ambient light sensors. Similar to your smartphone, these sensors constantly monitor the light levels in your physical environment. When you are working in a brightly lit room or sitting near a sunny window, the operating system automatically increases the screen brightness so you can see your work clearly. Conversely, if you turn the lights out, the screen automatically dims to prevent eye strain and save battery life.

While this auto-brightness feature sounds excellent on paper, its real-world implementation is often frustrating. Windows 11 can be overly aggressive with its adjustments, causing the screen to flicker noticeably every time a cloud passes over the sun or you slightly change your posture, casting a shadow over the webcam. Furthermore, if you are doing colour-sensitive work like editing photographs or producing video, an automatically changing backlight will ruin your ability to accurately judge contrast and exposure.

If you prefer to manually control your screen brightness using the dedicated keys on your keyboard, you can easily disable the auto-brightness sensors within the Windows 11 system settings.

How to Turn Off Auto-Brightness (Adaptive Brightness)

Windows 11 manages your ambient light sensors directly within the primary display settings menu.

1. Click the Start button on your taskbar.
2. Select the Settings app (the gear icon). If you cannot find it, simply type “Settings” into the Start menu search bar.
3. In the left-hand sidebar of the Settings window, ensure System is selected.
4. On the right side of the window, click on Display (it should be the very first option at the top).
5. Look for the section labelled Brightness & colour.
6. Underneath the main brightness slider, look for a small checkbox labelled Change brightness automatically when lighting changes.
7. Click the checkbox to uncheck it.

Your screen will no longer react to the ambient light in your room. You are now entirely responsible for managing your screen brightness manually.

Note: If you are using a desktop PC with a standard monitor, you will likely not see this checkbox at all, as the vast majority of external monitors do not have built-in ambient light sensors. This feature is primarily found on laptops and high-end all-in-one machines like the Microsoft Surface Studio.

How to Turn Off Content Adaptive Brightness Control (CABC)

Even if you disable the ambient light sensor, you might still notice your screen mysteriously changing brightness. This is caused by a secondary feature known as Content Adaptive Brightness Control (CABC). Instead of looking at the light in your physical room, CABC looks at the content currently displayed on your screen.

If you are reading a bright white Word document, Windows increases the backlight. If you switch to a dark-themed application or watch a moody movie, Windows dims the backlight to save battery life. Many users find this constant shifting incredibly annoying.

Here is how to disable CABC so your backlight remains completely static:

1. Navigate back to the same Settings > System > Display menu used in the previous step.
2. Look at the main Brightness slider.
3. To the right of the brightness slider, you will see a small, downward-facing arrow. Click this arrow to expand the advanced brightness options.
4. Look for a drop-down menu labelled Change brightness based on content.
5. Click the drop-down menu and change the setting from “On Battery Only” or “Always” to Off.

With both the ambient light sensor and CABC disabled, your Windows 11 display will remain at a constant, steady brightness level until you manually adjust it.