Last Updated: August 2026
You came here to download f.lux for your Mac. Here is the link: justgetflux.com. It is free, it still installs, and on most Macs it will still warm your screen tonight.
That is the honest answer to the question you actually asked, and it goes first.
What follows is the part that is not printed above the download button: the Mac build waiting on the other side of that link was compiled on 17 May 2023. Not marketed as of 2023 — compiled. You can confirm it yourself in one line, and this post will show you how.
Where to Download f.lux for Mac
Download f.lux for Mac from justgetflux.com, the developer's own site. The Mac download is a ZIP archive of roughly 2.1 MB containing version 42.2. It is free, there is no account, and there is no trial timer.
The direct file link is justgetflux.com/mac/Flux.zip, which redirects to f.lux's CDN at macflux.b-cdn.net. That redirect matters in a moment.
Use the official site rather than a download portal. Software mirrors frequently list their own upload date as the release date and sometimes serve an older build than the vendor does, so a listing that looks freshly updated may be neither current nor the file f.lux would give you. When the original is free and one click away, a mirror adds risk and subtracts nothing.
Is f.lux Still Being Updated for Mac?
The Mac build, no. The company, yes. Those are two different questions, and almost every page that ranks for this search collapses them into one wrong answer.
The macOS binary f.lux ships today carries a last-modified date of 17 May 2023. Its version is 42.2, and f.lux's own update feed at justgetflux.com/mac/macflux.xml contains exactly one entry, dated 1 June 2023. That single entry is the complete Mac release history the app advertises to itself.
The Windows installer tells a completely different story. It is dated 8 April 2026.
curl -sI -L https://justgetflux.com/mac/Flux.zip | grep -i last-modified
curl -sI -L https://justgetflux.com/flux-setup.exe | grep -i last-modifiedTwo lines, two dates: Wed, 17 May 2023 and Wed, 08 Apr 2026. We measured both twice, on separate days, following the redirects to the files actually served.
So f.lux is not abandoned software from a developer who disappeared. It is an actively maintained Windows application whose macOS build stopped three years ago. Anyone telling you f.lux is dead is wrong. Anyone telling you the Mac version is current is also wrong. The truth is narrower and more specific than either.
What f.lux Got Right
f.lux invented this category. In 2009, when the idea that a screen's colour temperature had anything to do with human sleep was a fringe position, Michael and Lorna Herf shipped software that warmed your display as the sun went down. Not as a novelty. As a considered response to the circadian literature, years before the mainstream caught up.
Apple did not ship Night Shift on the Mac until macOS Sierra 10.12.4 in March 2017 — eight years later. Every warmth slider on every operating system today is downstream of a decision two people made in 2009. That deserves saying plainly rather than as a throat-clearing concession before an attack.
It is also still, in a real sense, good software. f.lux goes to 1200K, well past Night Shift's 2700K floor. Its scheduling is more thoughtful than Apple's. It is free, with no upsell and no account. If you installed it in 2015 and never thought about it again, it served you well, and nothing here is an argument that you were wrong.
And the lights are still on. The Windows release from April 2026 is recent work, and f.lux's macOS support forum — over 1,100 topics deep — still sees posts this year. This is not a story about a company that vanished.
The argument is narrower than that: the Mac in front of you is not the Mac f.lux was last built for.
How to Install f.lux on a Mac
Installation is four steps and takes about a minute:
- Download the ZIP from justgetflux.com and let Safari or your browser unzip it.
- Drag
Flux.appinto your Applications folder. Running it from Downloads works but breaks the moment you clear that folder. - Open it. On first launch macOS will ask you to confirm an app downloaded from the internet. This is normal Gatekeeper behaviour, not a warning about f.lux specifically.
- Grant location access when prompted, or type your city manually. f.lux needs to know where you are to know when your sun sets.
To have it start automatically, add it under System Settings → General → Login Items. f.lux has its own "start at login" checkbox too; either works.
One note that catches people out: because the build predates several macOS permission changes, the sequence of prompts you get on a current Mac may not match the screenshots in older tutorials. Nothing is broken if the order looks different. Grant location, and you are done.
Is f.lux Safe to Download?
Yes. It comes from the developer's own domain over HTTPS, it has been distributed the same way for over a decade, and there are no known security problems with it. Let us be unambiguous, because "abandoned software" and "unsafe software" are different claims and only the first one is on the table here.
The real risk with a 2023 binary is not safety. It is fit. Software that reaches into the display layer is not like a text editor that keeps working forever — it is a plug in a socket the operating system keeps rewiring. macOS has shipped several major versions since that build was compiled, each with its own changes to how displays, colour profiles, and permissions are handled. An app that has not been rebuilt against any of them is running on inertia.
f.lux vs Night Shift vs Sundown: How Deep Each One Goes
Colour temperature is the one specification you can compare directly, because it is measured in Kelvin and every app publishes its floor. Lower is warmer. Lower is what your body reads as "evening."
| Night Shift | f.lux | Sundown | |
|---|---|---|---|
| Warmest setting | 2700K | 1200K | 500K |
| PWM flicker-free mode | No | No | Yes |
| Latest Mac release | Ships with macOS | 17 May 2023 | 19 Aug 2026 |
| Price | Free | Free | $29/year |
Those two dates in the third row are both public artifacts. f.lux's comes from the HTTP header above. Sundown's comes from our published update feed at trysundown.com/appcast.xml, which lists version 1.4.10 dated 19 August 2026. Neither number requires you to trust a marketing page.
The gap between 1200K and 500K is the part worth understanding. 1200K is deep amber — roughly a candle. 500K is a red so deep it looks like a darkroom for the first two evenings, and then looks normal. That difference is not cosmetic; it is the difference between reducing the short-wavelength light your screen emits after dark and very nearly removing it.
What the Science Actually Supports
Here is where most app comparisons overclaim, so we will do the opposite.
Ostrin et al. (2017) found blue-blocking lenses raised nocturnal melatonin ~58% in healthy adults, who also slept ~24 minutes longer. That study — Ostrin, Abbott and Queener, published in Ophthalmic & Physiological Optics, PMID 28656675 — is the strongest single result in this area, and it is about lenses worn over the eyes, not about display colour temperature.
The counterweight belongs in the same paragraph. A 2023 Cochrane review by Singh, Keller, Busija and McMillan (PMID 37593770) examined blue-light-filtering spectacle lenses and found the evidence for visual performance and sleep outcomes weak and inconsistent. Anyone selling you a screen filter should be willing to tell you that paper exists.
Our full citation list, including the Cochrane review, lives on the Sundown science page. We put the paper that argues against us on our own site on purpose.
If f.lux Won't Launch: What to Try First
The failure people report most often is not a crash — it is f.lux appearing to run while the screen stays cold, or the warmth reverting on its own.
Things that are worth trying, in order:
- Check for a conflicting filter. Night Shift and f.lux both write to the same display gamma table. If both are on, the result is unpredictable. Turn Night Shift off in System Settings → Displays → Night Shift.
- Re-grant location access. System Settings → Privacy & Security → Location Services. If f.lux does not know where you are, it does not know when to start.
- Quit and relaunch after connecting an external display. Display hot-plugging is the most common trigger for a filter losing its grip on the gamma table.
- Restart. Genuinely — gamma-level state is one of the few things a reboot reliably clears.
And the thing that does not help, which people try first: reinstalling. Downloading the ZIP again gets you a byte-identical copy of the same 2023 binary. There is no newer Mac build waiting behind a fresh download, so a reinstall changes nothing about compatibility. Save yourself the round trip.
Should You Still Use f.lux in 2026?
If you want a free warmth filter, you are happy at 1200K, and it works on your machine — then yes. Keep it. It costs nothing, it does the thing, and we are not going to pretend that a working free app is a crisis.
Reconsider if any of these are true: you are on recent Apple Silicon and you get headaches at low brightness, you want to go meaningfully deeper than amber, or you would rather run software that is still being built for the OS you are actually using.
That last one is the whole case, and it is a preference rather than a verdict. A 2023 binary is a 2023 answer to a question macOS has re-asked several times since.
Sundown reaches 500K, includes a PWM flicker-free dimming mode that neither f.lux nor Night Shift offers, and shipped its most recent release on 19 August 2026. There is a 7-day free trial at trysundown.com — install both, run f.lux one evening and Sundown the next, and let your own eyes settle it. If f.lux wins, keep f.lux.
Frequently Asked Questions
Is f.lux free?
Yes. f.lux is completely free on macOS with no account, trial period, or paid tier. It has been free since 2009.
What is the latest version of f.lux for Mac?
Version 42.2. f.lux's own update feed lists it with a date of 1 June 2023, and the binary itself carries a last-modified date of 17 May 2023. Download mirrors sometimes display their own upload date instead, which is why some listings look more recent than they are.
Does f.lux work on the current version of macOS?
It installs and generally runs. It has not been rebuilt for the macOS versions released since May 2023, so it has no native support for display changes introduced after that date. Compatibility, rather than security, is the thing to watch.
Is f.lux discontinued?
No. f.lux shipped a Windows update in April 2026 and its support forum is still active. It is the macOS build specifically that has not been rebuilt since 2023.
Is f.lux better than Night Shift?
On depth, yes — f.lux reaches 1200K against Night Shift's 2700K floor, and its scheduling is more flexible. Night Shift's advantage is that Apple updates it with every macOS release. See our full Night Shift vs f.lux comparison.
What should I use instead of f.lux on a Mac?
It depends on what is missing for you. If it is depth or flicker, Sundown goes to 500K and adds flicker-free dimming. We compare the full field in our guide to f.lux alternatives for Mac.
The Short Version
Download f.lux from justgetflux.com. It is free and it still works.
Then run the two commands in this post and look at the dates. One is the Mac build you just installed. The other is what the same developer shipped to Windows this year. Whatever you decide after that, you will have decided it on measured facts rather than on anyone's marketing — including ours.