Awesome Open Source
Awesome Open Source


This project is not being worked on anymore. A new, linux-only version is being developed here.


is a tool for adjusting pixel brightness/temperature automatically or manually.

It can dim the screen if its content is too bright, or brighten it otherwise. This can help your eyes adjust when switching between dark and light windows, especially at night or in suboptimal lighting conditions.

Screenshot available on its website.

Planned features

  • Proper multi-monitor support
  • Command line interface / configurable hotkeys
  • Location-based temperature adaptation
  • Backlight control




Visual C++ 2017


Get it here or here. Unpack and run it, no installation required.


If the sliders don't work beyond a certain value, start the app in admin mode once, then restart the system.

This disables a limit that Windows imposes on how much a program can change screen values.


Building from source


  • g++ or Clang compiler with C++17 support
  • Ubuntu/Debian packages:
sudo apt install build-essential libgl1-mesa-dev libxxf86vm-dev libxext-dev qtbase5-dev qtchooser qt5-qmake qtbase5-dev-tools

To install:

git clone
cd gammy
sudo make install

You can then find Gammy in your applications. To run it from the shell, execute: gammy

To uninstall:

sudo make uninstall

On GNOME, the Qt5 Configuration Tool is recommended to improve UI integration:

sudo apt install qt5ct



AUR packages are available:


On Gentoo-based distros, Gammy is included in GURU Gentoo overlay:

# emerge the tool to enable the overlay
sudo emerge -av app-eselect/eselect-repository
# Setup the GURU overlay
sudo eselect repository enable guru
sudo emaint sync -r guru
# Finally emerge gammy
sudo emerge -av --autounmask x11-misc/gammy


On FreeBSD, Gammy can be installed from ports:

% cd /usr/ports
# update your ports branch to the latest, with your preferred method
% cd accessibility/gammy
% sudo make install-missing-packages
% sudo make package
% pkg install ./work/pkg/gammy*

or from pkg, as soon as accessibility/gammy hits your (quarterly) repo:

% sudo pkg install -y gammy


The app appears maximized the first time you start it. On subsequent starts, it's minimized in the system tray. This can be changed by setting wnd_show_on_startup to true in the config file (~/.config/gammyconf on Linux).

The window is shown or hidden by clicking on the tray icon. In some configurations you might need to double click. You can close it by pressing Esc when it's focused.

The first Auto checkbox activates automatic brightness. The following sliders will be revealed (scroll or expand the window to see all of them):

  • Range: minimum and maximum brightness.
  • Offset: higher = brighter image.
  • Threshold: how much the screen has to change in order to trigger adaptation. The default value is generally good in most cases.
  • Adaptation speed: how quickly the brightness adapts when a change is detected.
  • Screenshot rate: the interval between each screenshot. Lowering this value detects brightness changes faster, but may increase CPU usage.

Automatic adjustments can be toggled on or off with a middle click on the tray icon.

The second Auto checkbox activates adaptive temperature. The ellipsis button (...) opens a window to control its time schedule, as well as the adaptation speed.

The padlock button allows the brightness range to go up to 200%. (Linux only)

Known issues and limitations

The brightness is adjusted by changing pixel values, instead of the LCD backlight. This has wildly varying results based on the quality of your screen.

Theoretically, this app looks best on OLEDs, since they don't have a backlight. (If you have one, I'd love to know your experience).

Backlight control is planned. However, not all screens support backlight control via software.

Multi-monitor issues

On Windows, currently the brightness is detected and adjustable only on the monitor that is set as the primary screen. Temperature affects all screens, however.

On Linux, currently every screen is treated as one single screen when calculating brightness. Both brightness and temperature are changed globally.



When building from source, if make fails with PlaceholderText is not a member of QPalette errors in ui_mainwindow.h, the Qt version provided by your distro is older than 5.12. As a workaround you can delete the offending lines in ui_mainwindow.h, then run make again.

If you are using a command to run it on startup, and the tray icon does not appear, try this.

If you are experiencing an "Invalid gamma ramp size" fatal error, refer to this post.

Third party

  • Qt 5 (LGPL)
  • Plog (MPL)
  • JSON for Modern C++ (MIT)
  • Qt-RangeSlider (MIT)


Copyright (C) Francesco Fusco.


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