Use F.lux To Adjust Monitor Color and Brightness By Time of Day


Do you often use electronics late into the night staring at bright, blue-light-emitting screens? This modern phenomenon is wreaking havoc on our natural circadian rhythms and making quality sleep harder to achieve. Fortunately, there is an easy software fix – f.lux.

F.lux is an ingenious program that automatically adjusts the color temperature and brightness of your computer screen to align with your natural sleep cycle. Keep reading to understand what f.lux is, why blue light harms sleep, and how to leverage f.lux for better sleep, eye health, and wellbeing.

What is F.lux and How Does it Work?

F.lux is a free program developed by researchers at the Lighting Research Center at Rensselaer Polytechnic Institute. The researchers found strong evidence that exposure to bright blue light at night from electronics severely disrupts the body’s circadian rhythm. Circadian rhythms regulate important biological processes based on natural cycles of daylight and darkness. But staring into bright screens late into the evening tricks your body into thinking it’s daytime.

This delays the release of melatonin, a hormone that signals sleepiness, and pushes your natural bedtime back by several hours. The end result is difficulty falling and staying asleep. F.lux aims to solve this problem by automatically adjusting the levels of blue light emitted from your digital screens based on the sun’s position. During the day, it uses your monitor’s full color temperature with enriched blues for maximum alertness.

But as the sun sets, f.lux gradually reduces the blue light and shifts your display to warmer, less disruptive colors for healthy nighttime use. Let’s look at the benefits of this approach.

Benefits of Using F.lux

There are several key benefits that make f.lux worth using:

  • Better sleep – By limiting blue light exposure at night, f.lux helps regulate your circadian rhythm so you can fall asleep faster and sleep more soundly.
  • Eye strain relief – The warmer color temperature is less harsh on your eyes, especially if you use the computer at night.
  • Headache reduction – Some studies have found that decreased blue light exposure can alleviate eye strain headaches.
  • Night mode alternative – F.lux is a more convenient solution than manually toggling on your monitor’s Night Mode setting.
  • It’s free! – You can’t beat the price. F.lux is completely free to download and use on your Windows, Mac, or Linux machines.

For the small hassle of installing a program, f.lux provides some nice benefits. Better sleep alone makes this a worthwhile upgrade for your computer.

How to Download and Install F.lux

Downloading and setting up f.lux is quick and easy:

  • Go to and click the download link for your Windows, Mac, or Linux machine.
  • Open the downloaded F.lux installer and walk through the installation prompts.
  • If prompted, allow F.lux to make changes to your system by granting admin access.
  • Once installed, F.lux runs in your system tray. Click on the icon to open settings.
  • In settings, you can sync F.lux with your timezone location so daylight/nighttime adjustments are made automatically.
  • Try toggling between Daytime and Night modes to preview the color difference.
  • Optionally set a custom schedule if you want daylight/nighttime transitions at specific times.

That’s all it takes to start using F.lux! It will now automatically adjust colors in the background whenever you use your computer.

F.lux Tips and Settings

Here are some handy tips for customizing F.lux on your system:

  • Sync your location so daylight/nighttime transitions align with actual sunset and sunrise.
  • Make color adjustments gradual over 60 minutes for a subtle, natural change.
  • Use the Presets tab to choose different color temperature presets.
  • Enable Darkroom Mode to eliminate all blue light for nighttime computer use.
  • Try toggling F.lux off/on at night to see the impact on your eyes.
  • Use the Disable for an hour option if you need full blue light at night.
  • Set a custom schedule if you go to bed earlier than sunset or use your computer late.
  • Play with the color slider to adjust the intensity of the color shift.

Take some time to dial in F.lux’s settings to your preferences. The more you customize it, the better the results.

Frequently Asked Questions

Here are answers to some common questions about the F.lux software:

Does f.lux affect monitor brightness?

No, f.lux only adjusts color temperature, not brightness. You’ll need to lower brightness manually at night.

Can f.lux be disabled temporarily?

Yes, you can easily disable f.lux for 1 hour if you need full blue light at night.

Will f.lux impact color accuracy?

It shifts colors slightly, but your eyes adjust within minutes without a noticeable change in accuracy.

Does using f.lux really improve sleep?

For most people, limiting blue light at night leads to faster sleep onset and higher quality sleep.

Is f.lux safe to use?

Yes, extensive use by millions of people has shown f.lux to be completely safe to use.

Can f.lux be used on multiple monitors?

Yes, f.lux works across multiple monitors connected to the same PC or Mac.

Does f.lux work with apps in fullscreen mode?

In most cases, yes, but some fullscreen DirectX games may not shift properly.

Hopefully, those tips answer any questions you might have about the capabilities of f.lux. It’s a simple yet powerful tool for improving sleep.

Alternatives to F.lux

F.lux is the most popular tool for adjusting color temperature, but there are a few alternatives:

  • Windows 10 Night Light – Built-in blue light reduction for Windows 10.
  • Iris Mini – Similar app for MacOS with added brightness adjustment.
  • Redshift – Open source color temperature software for Linux.
  • Twilight – Blue light filtering app for Android devices.

While some alternatives exist, f.lux remains the best option due to its extensive platform support, settings, and customization.

Should You Use F.lux?

If you regularly use electronics at night, then you should definitely try out f.lux. Limiting your blue light exposure in the evening provides real benefits for sleep and eye strain without any significant downsides. The one-time setup process is quick and easy. F.lux works automatically in the background every day to adjust the color based on the time. While the warmer lighting may seem unusual at first, your eyes quickly adapt to the change.

Many people don’t realize just how much blue light our devices emit at night. It’s worth installing F.lux just to get a sense of the difference it makes. Your eyes and sleep cycle will thank you! So download f.lux and give it a try tonight. Do you find it easier on your eyes at night? Do you fall asleep faster or sleep better? Let us know about your experience in the comments below! Sweet dreams!

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