f.lux

Complete guide to installing and configuring f.lux on Windows, macOS, and Linux to reduce eye strain and improve sleep.

What is f.lux?

f.lux is a software that adapts your computer display's color temperature according to the time of day. It makes the screen look like sunlight during the day and warm (like indoor lighting) at night.

Why Use f.lux?

• Reduce Eye Strain: Blue light is harsh on eyes, especially at night.
• Improve Sleep: Blue light suppresses melatonin. f.lux helps maintain your circadian rhythm.
• Better Aesthetics: Warm colors are more pleasant in low-light environments.

Installation

Windows

1. Download from justgetflux.com
2. Run flux-setup.exe
3. Accept the license agreement
4. f.lux will launch automatically

macOS

1. Download the Mac version from the official site
2. Unzip .zip file
3. Move Flux.app to your Applications folder
4. Open the app (you may need to allow it in System Preferences > Security)

Linux (Ubuntu/Debian)

f.lux has a GUI for Linux or a command-line version (xflux).

Install GUI version:

sudo add-apt-repository ppa:nathan-renniewaldock/flux
sudo apt update
sudo apt install fluxgui

Configuration

1. Set Location: Enter your zip code or coordinates so f.lux knows sunrise/sunset times.
2. Choose Lighting:
   • Daytime: 6500K (Daylight)
   • Sunset: 3400K (Halogen)
   • Bedtime: 1900K (Candle)

Features

• Movie Mode: Disables color shift for 2.5 hours while watching films.
• Darkroom Mode: Inverts colors and uses red tones (great for very dark rooms).
• Vignette Mode: Darkens borders of screens to focus on center.

Troubleshooting

• Flashing Screen: Update graphics drivers.
• Not Working on Fullscreen Games: Some games override color profiles. Run games in "Windowed Borderless" mode.

Alternatives

• Windows Night Light: Built-in feature in Windows 10/11 (Settings > System > Display > Night light).
• macOS Night Shift: Built-in feature (System Preferences > Displays > Night Shift).
• Redshift: Popular open-source alternative for Linux.