The best alternative to f.lux is Redshift, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to f.lux and four of them are so hopefully you can find a suitable replacement. Other interesting alternatives to f.lux are LightBulb, Twilight and Red Moon.
Redshift adjusts the color temperature according to the position of the sun. A different color temperature is set during night and daytime.
It doesnt't work sometimes...
It's just not as good as f.lux is.
Background application that adjusts screen gamma, making the colors appear warmer at night, reducing strain on your eyes.
user-friendly interface and easily configurable
Has a customizable schedule instead of 50 meme filters no-one will ever use.
Open source, far more options, faster
The app filters the blue spectrum on your phone or tablet after sunset and protects your eyes with a red filter. The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times.
The app is free on F-Droid and on GitHub but you can buy it on the Google Play Store to support the developer.
Straightforward. Fast. No ads. No trackers.
Denmark
EU
Ukraine
This is open source, while f.lux wants you to download a binary and run it constantly on your system.