Best f.lux Alternatives for Mac and Windows (2026)

The best f.lux alternatives in 2026 are Night Shift or Windows Night light if you want something free that is already on your computer, Abendrot if you want a free open-source Mac app, and LightBulb if you want a free open-source Windows app. Iris has a free version and lists the warmest setting of the free apps, and Drift, CareUEyes and CircadianShield cost between $19 and $47 to buy outright. Sundown, which we make, costs the most of the paid apps here, and it goes warmer than f.lux (a deep red against f.lux's deep orange) with flicker-free dimming on a Mac. If you have an M5 Pro or M5 Max MacBook Pro, read the section on that first, because a macOS bug stops f.lux and other apps that use a color table from changing the built-in screen.

I make Sundown, one of the apps on this list, so I'll say that up front. The numbered Mac list below is in price order, cheapest first, because what you pay is the first of the three things the choice comes down to, ahead of how warm you want it and which computer you're on. An app with a free version counts as free, and the paid apps are compared by the price to buy them outright, which every one of them offers. Where two cost the same, the one whose developer publishes the warmer setting comes first, and an app with no published figure comes after one that has it. Every fact about the other apps below comes from the developer's own site, store page or source code, and the link is next to it so you can check. Where a developer doesn't publish a number, the table says so. Every guide on this subject is collected under f.lux and alternatives.

f.lux alternatives compared

The Mac apps are in the same price order as the sections below, then the Windows apps and Redshift. Sources for each row are linked in that app's section, and prices and versions were read from each developer's site on 10 October 2026.

Why f.lux stops working on M5 Pro and M5 Max Macs

On MacBook Pros with the M5 Pro or M5 Max chip, macOS accepts the color table that f.lux and similar apps send and then doesn't show it, so the app looks switched on and the screen doesn't change. Apple has reproduced the bug and says it is still under investigation. Base M5 Macs and M4-era Macs are reported to work.

Most screen-warming apps, f.lux included, work the same way. They hand macOS a color table for each display, and the display uses it to pull down the blue and green channels. In March 2026 a developer reported on Apple's developer forum that this call had stopped working on macOS 26.3 and the 26.4 release candidate, on an M5 Pro, on a MacBook Neo's external display and possibly on the M5 Max, and that it broke f.lux, BetterDisplay, MonitorControl and Lunar together. An Apple engineer then reproduced it on an M5 Max running 26.3.1: the calls return success, reading the table back returns the values that were just set, and nothing changes on screen. The same test app works on a base M5.

That thread is still open. Apple's engineer wrote recently that the bugs "are still open and under investigation", and the reports in it now run from 26.3 through 26.5.1 and macOS 27. On the f.lux forum, f.lux's co-founder has said the problem hits the XDR displays on these models, that M4-era Macs work, and that they are waiting on Apple. So this is Apple's bug to fix, and f.lux is waiting on Apple.

Two things are worth knowing if you own one of these Macs. First, there was an earlier and separate Tahoe problem in the 2025 developer betas, where automatic brightness stopped color tables from applying. That one was fixed in beta 5, so older advice to turn off auto-brightness won't fix the M5 Pro and Max bug. Second, the apps that still warm these screens do it another way. BetterDisplay's FAQ tells M5 Pro, M5 Max and MacBook Neo owners to turn off its color-table control, leave its software video adjustments and compositor filter layer on, and test again, and Drift drives Apple's own Night Shift instead of writing a color table.

f.lux itself: still a good free option

f.lux still ships: its Windows build is dated 8 April 2026. The Mac build hasn't changed since 17 May 2023. It is free, it follows sunset where you live, and its warmest preset is a deep orange.

Those two dates are the ones on the download files f.lux serves today. f.lux is free on Mac and Linux and free for personal use on Windows, with paid licenses for companies. It asks where you live and what lighting you have, then warms the screen at sunset and clears it in the morning. Its FAQ lists the presets from Sunlight down to Ember, a deep orange, and it also has a Darkroom mode that turns the screen red and black. On a Mac you can tell it to switch off for a particular app, which helps if you edit photos in the evening.

The company is active and its developers answer in their forum. The trouble on a Mac is narrow: the Mac app is a 2023 build, and on M5 Pro and Max it can't get past Apple's bug. If you are on an older Mac and f.lux does what you want, there is no reason to switch. If you just want f.lux, our guide to downloading f.lux for Mac covers the install and how to check the build date.

Best f.lux alternatives for Mac

1. Iris

Iris runs on Windows, Mac and Linux, with a free version and paid upgrades: Iris Pro is $14.99 once, Iris mini Pro is $9.99, and a $1.99 monthly subscription covers both. It has a lot of settings, and its site says it controls brightness without PWM. Its help pages say the temperature runs from its warmest to ordinary daytime white and call the warmest "maximum blue light reduction", and its Sleep and Biohacker presets use that warmest setting at night. We compare it with Sundown in more depth in Sundown vs Iris for Mac.

2. Abendrot: free and open source

Abendrot is a free menu bar app under the MIT licence, with its source on GitHub (release 1.1.3 on 8 October 2026). It needs macOS 12 or later and runs on Apple silicon and Intel. Its everyday range stops a little short of f.lux's warmest and a Cozy mode goes further, to a near-red endpoint. It warms around your local sunset, has a hotkey to see true color for a moment, and comes with a command-line tool. Its README says that when direct warming isn't available on a display it falls back to a screen tint. If you want free and you want to read the code, this is the one to try.

3. Night Shift: free and already on your Mac

Night Shift is in System Settings under Displays. It runs from sunset until sunrise or on custom hours, and a slider makes it warmer or cooler. Apple doesn't publish a figure for the warm end of that slider. There is no dimming beyond your normal brightness and no per-app switch. If all you want is a gentle shift in the evening it does the job, and it costs nothing. Our Night Shift vs f.lux comparison goes through the two in detail.

4. Drift: built on Night Shift

Drift is a newer Mac app, launched on Hacker News this summer by a developer whose M5 Max stopped responding to f.lux. Instead of writing a color table, its site lists macOS Night Shift as the way it changes the display, with five schedules to choose from. Because of that, its developer says it warms M5 Pro and Max built-in screens, though how warm it goes is limited to Night Shift's range. Its site prices it at $19 once for up to two Macs, with a seven-day trial. I haven't been able to test it on an M5 Pro or Max.

5. CareUEyes

CareUEyes runs on Windows and on macOS 12 and later. Beyond a blue light filter it does break reminders, including breaks that lock the screen, and brightness control in 1% steps. Its site describes the color range as a broad scale, which tells you less than an actual warmest-preset figure would. It is $2.90 a month, $19.90 a year or $24.90 once for one PC, with a 7-day trial.

6. CircadianShield

CircadianShield is $47 once for Mac and Windows. It warms down to a little short of f.lux's warmest, follows the sun's elevation where you are, and dims with a software overlay so the hardware brightness can stay higher. It doesn't say anything about M5 Pro and Max.

7. Sundown: deep red, and flicker-free dimming

Sundown is a menu bar app I make for people who want the screen warmer and dimmer at night than the built-in tools allow. It goes from ordinary daytime white down to a deep red, where the gamma table passes red only, and it has seven warmth presets plus a custom setting. Its flicker-free mode holds the backlight at full power and does the dimming in the gamma table, so the dimming doesn't rely on the backlight's PWM. On Apple silicon it can also switch off the temporal dithering that shows up as a crawling shimmer at deep settings (more on that in display dithering on Mac). On the current Mac version you can set a custom schedule by time of day.

It costs $4.99 a month, $39 a year or $79 once, with a 7-day free trial. It runs on macOS 12 or later on Apple silicon and Intel. It has no per-app switch like f.lux, so turning it off is one global toggle.

At a deep orange setting the screen looks like a candle seen through honey. At the deepest setting it is a deep red, because the green and blue channels are switched off. For the full feature-by-feature version, see Sundown vs f.lux, and the Blue Light Calculator shows how much short-wavelength light each warmth setting leaves in.

On why flicker matters to some people at all, and how far the studies go, see Screen Flicker and Digital Eye Strain: The Evidence.

Best f.lux alternatives for Windows

On Windows, start with Night light, which is built in and free. If you want more control for free, LightBulb is open source and still maintained. f.lux itself is current on Windows too, with a build dated 8 April 2026.

Windows Night light

Night light is in Settings, System, Display. Microsoft's instructions cover the two controls it has: a Strength slider, and a schedule that runs from sunset until sunrise or on hours you set. Microsoft doesn't give a figure for full strength. Like Night Shift, it is the easy answer if you only want a gentle shift.

LightBulb

LightBulb is free and open source under MIT, for Windows on x64, x86 and ARM64. Version 2.7.2 came out on 10 September 2026. It moves the screen color through the day by your location or by sunrise and sunset times you set, with hotkeys and a list of apps to leave alone. In its source code the night slider defaults to a very warm lower end, while its settings allow down to a deep red, and brightness can go down to 10% through the gamma ramp. Of the free Windows options it has the most control.

SunsetScreen

SunsetScreen is a small tray app: a week's free trial, then $5. You set the exact sunset and sunrise times, choose the evening color by color temperature or by an exact hue, and it can lower overall brightness. Its current version is 1.50, dated August 2022.

Sundown for Windows (coming soon)

Sundown is for Mac for now. Windows is coming soon, and you can join the Windows waitlist to hear when it's ready.

Iris, CareUEyes and CircadianShield also run on Windows, and they're covered in the Mac section above.

Redshift, and the night lights built into Linux desktops

Redshift is the long-standing open-source option (GPL-3.0). It is best known on Linux, but its source also carries macOS (Quartz) and Windows backends, and its README links Windows builds. It adjusts the gamma ramps by your location and has a brightness option. Its last release, 1.12, came out in May 2018 and the repository is now archived, so whether it still works on a current Mac is untested. Its own README points out that GNOME (Night Light) and KDE Plasma (Night Color) have the same thing built in, and on a current desktop that is the place to start.

Which f.lux alternative should you pick?

Most apps like f.lux do the same basic job of warming the screen after sunset, so the choice comes down to what you pay, how warm you want it and which computer you're on.

• You want free and simple: Night Shift on a Mac, Night light on Windows. Both are already installed.
• You want free with more control: Abendrot on a Mac, LightBulb on Windows. Both are open source.
• You want a deep red setting with flicker-free dimming on a Mac: Sundown, which goes down to a deep red and has a flicker-free mode that doesn't lean on the backlight's PWM. The 7-day free trial is enough to compare it with what you use now.
• You want one app on Mac and Windows: Iris, CareUEyes or CircadianShield, or f.lux itself.
• You need per-app exceptions for color work: f.lux on a Mac, or LightBulb on Windows.

If you're specifically looking for a Night Shift alternative that goes deeper, that guide explains how far Apple's built-in filter goes.

How to switch from f.lux to Sundown

Switching takes five steps.

1. Download Sundown from trysundown.com, open the download and drag it into Applications.
2. Quit f.lux from its menu bar icon, because two apps changing the display color at once give unpredictable results.
3. Open Sundown and pick a preset. Start at a deep orange if that's what you're used to, then try deeper.
4. Turn on flicker-free mode if you want dimming that doesn't rely on the backlight's PWM, and anti-dithering if you see shimmer at deep settings.
5. Uninstall f.lux when you're ready by dragging it to the Trash.

Frequently asked questions

What is the best free f.lux alternative?

On a Mac, Night Shift if you want nothing to install and Abendrot if you want more range and open source. On Windows, Night light if you want nothing to install and LightBulb if you want more control. f.lux is free too, and still a reasonable choice outside the M5 Pro and Max.

Does f.lux work on an M5 MacBook Pro?

On a base M5, yes, as far as the reports go. On an M5 Pro or M5 Max, f.lux runs but the built-in screen doesn't change, because of a macOS bug Apple has reproduced and not yet fixed. The same bug affects other apps that use a color table, such as BetterDisplay, MonitorControl and Lunar.

What is the best f.lux alternative for Windows 11?

Night light is built in and free. LightBulb is the free option with the most control. f.lux's Windows build is current, dated 8 April 2026, so it is still a fair choice there.

Can I run Sundown and f.lux at the same time?

I don't recommend it, because two apps changing the display color at once give unpredictable results. To compare them, use f.lux for a few evenings at its deepest setting, then switch.

Why does Sundown cost money when f.lux is free?

Sundown is paid for directly, and the things that cost money to build and maintain are the ones f.lux doesn't offer on a Mac: settings warmer than f.lux's deep orange, flicker-free mode and anti-dithering. The 7-day free trial lets you test all of it first. The research behind evening light and sleep, and what it does and doesn't show, is on the Sundown science page.

Further reading

• Sundown vs f.lux: the two apps compared setting by setting.
• Sundown vs Night Shift: the built-in option, compared setting by setting.
• Best blue light app for Mac: the Mac-only shortlist, if you don't need Windows.
• What color temperature means on a Mac screen: why a deep orange and a deep red look so different.