f.lux 4.120

Download f.lux

F.lux is a software that is aimed at maintaining user’s normal daily rhythm and sleeping schedule. The product is distributed for free under the EULA license and contributes to comfort pastime at a computer in the evening and nighttime.

The basis of the program is the mechanism of display temperature change that allows to decrease eyes fatigue and raise the level of melatonin. In its turn it helps to improve the quality of your sleep. The mentioned approach is based on the modern vision of scientists about the so called circadian rhythms and influence of illumination on the natural behavior of the sleep-awake process.

Smooth change of the display temperature that is used in f.lux resembles the smoothness of sunrise and sunset. Thus, the program simulates the mentioned processes which can be adjusted manually or automatically by linking to the user’s location. Screen brightness can also be adjusted by the f.lux’s tools. So, the program offers several ready glow options that are related to different light sources like candle, sunlight, fluorescent and halogen lamps, etc. Additional options allow to use various color themes and turn on the dark room mode (or night mode) when intellectual color inversion scheme is used that is very similar to the process of obtaining negatives of photos.

The interface is quite user-friendly. The main window is compact and the menu is hidden behind the hamburger button. The central zone shows the screen temperature scale and the current schedule of virtual sunrises and sunsets. Access to the control elements is fast and intuitive. Temperature control is done smoothly and easy due to the large scroll box.


  • Free of charge.
  • Smooth screen temperature control.
  • Schedule adjustment.
  • Ready presettings and modes.
  • Night mode, intellectual color inversion.
  • Supports the screen vignette function.
  • Finds user location to synchronize the screen temperature with the real illumination level outside and inside the room.
  • Quick installation.
  • Supports preview of the program performance based on the current settings.


  • Relatively weak support of different locations. In other words, the program is unable to find many big cities on its map.


f.lux works correctly. Flexible schedule settings and smooth transitions like “day-night” make adaptation of the user’s eyes to new illumination conditions easier wherever he is located – office, dark room or near the terrestrial poles.

Changes in recent version

Author: Flux Software LLC
Price: Free
Windows: 8, 10

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