Prolonged use of computer displays is a common cause of eye fatigue, a challenge that even the most advanced screen technologies have yet to fully overcome. Spending extensive periods in front of a PC, laptop, tablet, or smartphone inevitably leads to discomfort, prompting numerous companies to develop solutions.

f.lux is a free, lightweight application designed to combat this issue by dynamically adjusting your LCD display’s color temperature throughout the day. It works in the background, automatically adapting screen brightness and warmth to align with natural light cycles, thereby helping to reduce eye strain and promote better sleep patterns.

In This Post

Download f.lux

File size: 672KB

OS support: Windows

Windows

f.lux 4.141 Final

Notable Features

Automatic Color Adjustment: f.lux automatically shifts your screen’s color temperature from bright white during the day to warmer, orange-red tones at night. This dynamic adjustment helps your eyes feel more comfortable and aligns with your body’s natural circadian rhythm.
Location-Based Timing: The software uses your geographical location to determine local sunrise and sunset times, ensuring that the color temperature adjustments are perfectly synchronized with your natural daylight cycles. This personalized schedule adapts daily throughout the year.
Customizable Color Temperature: Users can fine-tune the color settings to their preference, with options to expand the color range for deeper warmth or choose from various presets. f.lux learns your preferences, allowing for a truly personalized viewing experience.
Temporary Disable Options: For tasks requiring accurate color rendering, such as image editing or watching videos, f.lux offers options to temporarily disable its effects for an hour, until sunrise, or for specific applications. This ensures color integrity when needed.
Bedtime Mode: An extra-warm Bedtime mode helps prepare you for sleep by further reducing alerting light. This feature can be customized to work with your actual sleep schedule, promoting better rest.
Smart Lighting Integration: f.lux can integrate with smart lighting systems like Philips Hue, allowing your indoor lights to automatically adjust their color temperature in sync with your screen, creating a cohesive and comfortable environment.
Keyboard Shortcuts: Convenient keyboard shortcuts are available for quick adjustments, such as dimming the screen, enabling/disabling f.lux temporarily, or activating specific modes, enhancing usability and control.
Multiple Monitor Support: The software offers support for multiple monitors, allowing for consistent color temperature adjustments across all connected displays, or even per-monitor disabling for specific setups.

Software Specifications

Software Name	f.lux
Version	4.141
License	Freeware
File Size	672KB
OS Support	Windows
Language	English
Developer	F.lux Software LLC
Homepage	https://justgetflux.com/
Changelogurl	https://justgetflux.com/news/
Last Updated	May 29, 2026

System Requirements

Minimum

OS: Windows 7, 8, 10, 11
Processor: Any modern Intel or AMD processor
RAM: 2GB minimum
Disk Space: 10MB of free space

Setup Instructions

Show Installation Steps

Installation Steps

Click the download button above to get the installer for your operating system
Locate the downloaded file (e.g., flux-setup4-140.exe) and double-click to run the installer
Follow the on-screen installation wizard to complete setup. You may need to enter your location and usual wake time for optimal performance.
Adjust color settings using the slider in the f.lux menu, typically found near your system clock, to find a comfortable balance.

Compatibility: Compatible with Windows 7 and later versions. For macOS, it supports OS X 10.9 or later.

Troubleshooting

Show Common Issues

Issue: Installation fails → Solution: Run the installer as administrator.
Issue: Screen remains tinted after quitting f.lux → Solution: Disable automatic brightness settings in your system preferences and then reboot your computer.
Issue: Flickering or tinted screens on Windows 10 → Solution: Ensure your video drivers are up to date by checking Windows Update or your manufacturer’s website.