RedDimmer
RedDimmer vs f.lux
Looking for a free f.lux alternative for Mac? RedDimmer puts warmth, software brightness and editable presets together in a small menu-bar app. f.lux remains a good choice for automatic color changes built around your day.
Choose RedDimmer for direct control of software brightness and warm-to-red color in one place. Choose f.lux for its location and wake-time-based color routine. Both are free, and f.lux also has a red Darkroom mode.
Try RedDimmer's interactive preview →RedDimmer's Mac App Store release is in preparation.
RedDimmer and f.lux: at a glance
| What matters | RedDimmer | f.lux |
|---|---|---|
| Price | Free; no subscription | Free for Mac |
| Everyday controls | Separate warmth and software-brightness sliders | Daytime, sunset and bedtime color settings |
| Red option | Pure-red setting; no color inversion | Darkroom effect with color inversion |
| Automation | Local sunset/sunrise or fixed-time schedules | Location and wake-time-based color schedule |
| Color-sensitive work | App exceptions and temporary pauses | Current-app exception and temporary disable |
| Getting it | Mac App Store release in preparation | Mac download on the official website |
f.lux references: f.lux: free Mac download ↗ · Official f.lux Mac guide: schedules, effects and exceptions ↗
A softer screen, with two separate controls
A warm screen can still look too bright in a quiet room. RedDimmer gives brightness its own slider, from 100% down to 10%, alongside the warmth slider. You can save the combination you like instead of deciding on color alone. For example, keep a neutral daytime preset, an amber evening preset and a much darker red preset for late use. These are choices about how the screen looks, not calibrated light measurements.
Explore RedDimmer's evening controls →When f.lux is the better fit
If your main goal is a color routine that follows daylight and your usual wake time, look closely at f.lux. Its Mac guide describes separate daytime, sunset and bedtime settings, temporary disabling and exceptions for the current app. Its Darkroom effect includes red output and color inversion. Red color is therefore not exclusive to RedDimmer; the choice is about the controls and routine you prefer.
f.lux: free Mac download ↗ · Official f.lux Mac guide: schedules, effects and exceptions ↗
For reading or writing after sunset
Start with the room and the work you are doing. Pick a brightness that leaves text easy to read, then choose a warmth you enjoy. RedDimmer's editable Evening preset makes that combination easy to revisit, while its local schedule can apply settings at fixed times or sunset. If you spend most of your day checking colors, use an app exception or pause the adjustment rather than judging an image through a tint.
Compare the appearance on your own display, keep text readable, and return to normal color for color-sensitive work. Our linked research explanations separate screen preferences from health claims.
Questions before you choose
Is RedDimmer a free alternative to f.lux?
Yes, RedDimmer is free and combines software dimming with warm-to-red color control. Its Mac App Store release is being prepared; f.lux has an existing Mac download.
Does f.lux have a red screen mode?
Yes. The official Mac guide describes a Darkroom effect with red output and color inversion. RedDimmer's pure-red setting does not invert the image.
Should I run f.lux and RedDimmer together?
Start with one app controlling color. Overlapping adjustments can make the result harder to understand. Pause or quit the other color controller before comparing the appearance on your Mac.
Sources and how we compare
f.lux: free Mac download ↗ · Official f.lux Mac guide: schedules, effects and exceptions ↗
This comparison is written by Guiix, the maker of RedDimmer. It uses the official product descriptions linked above and RedDimmer's current features. It is a feature guide; it does not report a head-to-head hardware test, clinical study or independent review. Other product names belong to their respective owners. Check the official release notes and license terms for the version you choose.
A softer screen for your evenings.
Free warmth and dimming. Editable presets. A routine that fits your day.
Mac App Store release in preparation.