How to Enable Automatic Brightness in Ubuntu Linux

Automatic brightness in Ubuntu Linux changes your screen brightness to match the light around you, using your laptop’s built-in ambient light sensor. It saves battery life and reduces eye strain by dimming the display when you move to a dark room.

Ubuntu 22.04 LTS and later include the feature, and you turn it on from the Settings app. It only works if your hardware has an ambient light sensor. Many laptops do, but desktops and some budget laptops don’t. If yours has no sensor, Ubuntu hides the switch, which is covered further down.

How to enable or disable automatic brightness in Ubuntu Linux

With automatic brightness on, your screen dims in dark rooms and brightens in sunlight without you touching the brightness keys. The short version is: open Settings, go to the Power panel, and turn on the automatic screen brightness switch. The numbered steps below walk through it.

The first way is through the Activities overview:

1. Click Activities in the top-left corner of the screen, or press the Super key (the Win on most keyboards).
2. Type Settings in the search🔍 box. You should see the Settings⚙️ app, shown with a gear icon.
3. Click the Settings icon to open it.

The second way is through the System menu in the top-right corner of your desktop. It is the group of icons for network, volume and battery.

1. Click the System menu in the top-right corner. A panel opens with the volume slider, network options and power controls.
2. Select Settings (the gear icon), as shown below. The Settings⚙️ window opens.

1. In the Settings app, look at the sidebar on the left and click Power. The Power panel opens on the right.

2. Find the Power Saving section in the Power panel.
3. Switch the Automatic Screen Brightness toggle to On. The switch changes colour to show it is active.

The change applies right away. You don’t need to restart or log out. Cover the sensor or move to a darker spot and the screen should dim within a few seconds. Exact wording and placement can differ slightly between Ubuntu releases, so look for the automatic brightness switch in the Power panel if the label is a little different.

If the toggle is missing, your laptop most likely has no ambient light sensor, or Ubuntu can’t read it. Nothing in Settings will add the option in that case. You can still adjust brightness by hand with the brightness keys or the slider in the System menu.

To turn automatic brightness off again, return to Settings › Power and flip the switch to Off. Your screen then stays at whatever level you set by hand.

That’s it. Your setting is saved, so you can close the Settings app. It will stay in place after you restart your computer.

Conclusion:

• Ubuntu Linux’s adaptive brightness feature adjusts the screen’s brightness based on surrounding lighting conditions, providing optimal brightness and contrast levels while saving power and prolonging battery life.
• Enabling automatic brightness ensures the screen is always easy to see in different ambient light conditions and helps reduce battery consumption.
• To enable or disable automatic brightness in Ubuntu Linux, open Settings, go to the Power panel, and set the Automatic Screen Brightness switch to the position you want. If the switch doesn’t appear, your device probably has no ambient light sensor.

Adaptive brightness keeps your display easy to read and extends battery runtime as the lighting around you changes.