f.lux (pronounced "flux") is a cross-platform computer program that adjusts a display's color temperature according to location and time of day, offering functional respite for the eyes. The program is designed to reduce eye strain during night-time use, helping to reduce disruption of sleep patterns.
On installation, the user can choose a location based on geographic coordinates, a ZIP code, or the name of a location. The program then automatically calibrates the device display's color temperature to account for time of day, based on sunrise and sunset at the chosen location. At sunset, it will gradually change the color temperature to a warmer color and restore the original color at sunrise.
f.lux offers a variety of color profiles and pre-defined temperature values, modifying program behaviour for specific programs or activities; including a mode for film watching, decreasing red tinge (for 2.5 hours), and a darkroom mode that does not affect night-adapted vision. Times can be inverted on f.lux for PC to provide warm lighting during the daytime (for people who work at night). The program can control Philips Hue LED lighting, so that the color temperature of house lights follows f.lux's settings.
What is f.lux?
f.lux by f.lux Software LLC (developed by Michael Herf) is proprietary Windows software in the monitoring & benchmarks category. It ranks 21st by popularity among monitoring & benchmarks in this catalogue. The first release dates back to 2009. Besides Windows, it is available for iOS, Linux and macOS.
Installation and requirements
The publisher provides EXE (NSIS) installers for 32-bit Windows. The main installer is 690 KB. It can be installed for the current user only, without administrator rights. A silent install is possible with the installer’s documented switches.
Updates and version history
The current version is 4.141, released on May 25, 2026. The version history goes back to February 5, 2024: 3 releases, all linked to the official files. That is about 1.3 releases a year.
Popularity and file types
The Chocolatey package has been downloaded 179,120 times. Wikipedia has an article about it in 13 of our languages. Similar programs include Veyon, Datadog Agent and windows_exporter.
Pros / Cons
Pros
- Documented silent install
- Installs without administrator rights
- Small download (690 KB)
- Also runs on iOS, Linux and macOS
- Mature project (since 2009)
Cons
- Proprietary licence: check the terms and price
- No native ARM64 build
- 32-bit only
In short: f.lux is a monitoring & benchmark tool for 32-bit PCs. Administrators can deploy it unattended.
Screenshots
Is f.lux safe to download?
- The file is served by justgetflux.com, the publisher’s own domain
- The download link uses HTTPS
- A SHA256 hash is published, so you can verify the file:
F035D1C4CD78468D76407AFBB90CE4B73B2D04B7647C0D6143969A1823CFF1AE· Open the VirusTotal report for this hash - The link answered when we last checked it (October 22, 2026)
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 3 versions ›3 versions over 2 years · about 1.3 a year
| Version | Date | Size | Files |
|---|---|---|---|
| 4.141Latest | May 25, 2026 | 690 KB | 32-bit EXE (NSIS) |
| 4.134 | March 14, 2024 | 687 KB | 32-bit EXE (NSIS) |
| 4.131 | February 5, 2024 | 690 KB | 32-bit EXE (NSIS) |
Install from the command line
Silent install ›winget install --id flux.flux -echoco install f.lux.install -yscoop install extras/fluxflux-setup4-141.exe /SRelated guide: How to use winget: install and update apps
Also for other systems
brew install --cask flux-appInformation
- Publisher
- f.lux Software LLC
- Developer
- Michael Herf
- Category
- Monitoring & benchmarks
- Licence
- Proprietary
- Price
- See the publisher’s site
- Interface languages
- English
- Requires
- Windows 11 / 10
- Architecture
- 32-bit
- Installer
- EXE (NSIS)
- Other platforms
- iOS, Linux, macOS
- Version
- 4.141
- Released
- May 25, 2026
- First release
- 2009
- Added to the catalogue
- February 5, 2024
- Versions listed
- 3
- Updates / year
- 1.3
- Chocolatey downloads
- 179,120
- Website
- justgetflux.com
- winget ID
- flux.flux
- Chocolatey package
- f.lux.install
- Scoop package
- extras/flux
Ratings and reviews
No reviews yet. Be the first to rate it.
Alternatives to f.lux
See all ›-
Veyon4.11.4.0Veyon is a free and open source software for monitoring and controlling computers across multiple platforms.Open source258.6K ↓ -
Open source870K ↓ -
Open source535K ↓ -
Open source128.6K ↓ -
LibreHardwareMonitor0.9.6A free software fork of Open Hardware Monitor that can monitor the temperature sensors, fan speeds, voltages, load and clock speeds of your computer.Open source85K ↓ -
Monitorian4.16.2Monitorian is a Windows desktop tool to adjust the brightness of multiple monitors with ease.Open source10.4K ↓ -
Mem Reduct3.5.2Lightweight real-time memory management application to monitor and clean system memory on your computer.Open source20.8K ↓ -
DiskSpd2.3DISKSPD is a storage load generator / performance test tool from the Windows/Windows Server and Cloud Server Infrastructure Engineering teams.Open source36.3K ↓
Frequently asked questions
Is f.lux free?
f.lux is proprietary (closed-source) software (licence: Proprietary). Whether it costs money depends on the edition: check the publisher’s site for prices and free tiers.
Is f.lux safe to download?
The download comes from justgetflux.com, which belongs to the publisher; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install f.lux with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Can f.lux be installed silently?
Yes. The silent install page lists the exact command for each installer.
Does f.lux run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 32-bit version through emulation.
Where can I download an older version of f.lux?
The versions page lists all 3 versions with links to their official installer files, back to February 5, 2024.
Can I use f.lux without administrator rights?
Yes, there is a per-user installer that does not need administrator rights.
What are alternatives to f.lux?
Veyon, Datadog Agent, windows_exporter, Alloy and LibreHardwareMonitor. The alternatives page compares them.
