Quick Answer: f.lux was the original evening screen-warming tool, released in 2009. Apple Night Shift (2016) and Windows Night Light (2017) followed. The Canadian Sleep Society endorses warming screens at night for melatonin protection. f.lux still dims the warmest and offers the most control, but for most users the built-in OS version is good enough.
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A brief history of screen warming
f.lux was released in 2009 by Michael and Lorna Herf, a small husband-and-wife team. The premise was simple: computer monitors emit more blue light than evening indoor light should, this suppresses melatonin, and software could warm the screen after sunset to match the ambient light in your room. For seven years, f.lux was the only serious option. Then, in March 2016, Apple shipped Night Shift in iOS 9.3; a year later, macOS got the same feature natively. Microsoft followed with Windows Night Light in April 2017. Android added a similar Night Light to stock versions in 2018, though manufacturers had offered flavour of it earlier.
This matters because most sleep advice from the 2010s is implicitly about f.lux. In 2026, most readers have a native option already built into their device and do not realise it. The current question is less "should I install f.lux" and more "which version is on my device, and is it set up correctly."
The underlying premise, briefly
Evening exposure to short-wavelength light (around 450 to 480 nm) suppresses pineal melatonin secretion through the melanopsin pathway, delaying sleep onset and shifting the circadian phase later. The Canadian Sleep Society, Mayo Clinic, and the Sleep Foundation all list evening screen light management as part of sleep hygiene. Warming a screen reduces the blue component. A 2025 Frontiers in Neurology meta-analysis we cover in our blue-light blocker evidence review found the sleep effect of evening screen warming is real but modest, comparable to wearing blue-light glasses.
Medical disclaimer: this is general information, not medical advice. If you have a diagnosed circadian rhythm disorder, please work with a sleep specialist.
On macOS: f.lux vs Night Shift
If you use a Mac after 2017, Night Shift is already on your system. System Settings, Displays, Night Shift tab. Schedule it sunset-to-sunrise, slide warmth toward the warm end.
When Mac users should pick which
- Stick with Night Shift if: you like simple, you want it to just work, you are not chasing maximum blue-light reduction. For most users, Night Shift at "more warm" is sufficient.
- Install f.lux if: you want warmer dimming than Night Shift can produce (several reviewers have measured f.lux cutting about twice as much blue light at maximum), you want per-app exceptions (Night Shift cannot exclude photo-editing or colour-critical work), or you want multiple sunset/dusk/bedtime steps rather than a single transition.
- Run both: not recommended. They fight each other. Pick one.
For professional work where colour accuracy matters (design, photo editing, video colour grading), either tool interferes with the work. f.lux lets you add specific applications as exceptions; Night Shift does not. That alone pushes many creatives to f.lux.
On Windows: f.lux vs Night Light
Windows 10 added Night Light in April 2017. Windows 11 kept it. Settings, System, Display, Night Light. Similar to Night Shift in ease and limitations.
Windows-specific notes
- Night Light is subtler than f.lux by default. The Windows warm setting is noticeably less aggressive than f.lux on medium. If you want a warmer screen, f.lux still wins on Windows.
- Night Light supports scheduling, including sunset-to-sunrise. Manual schedules work too. Set it and forget it.
- f.lux offers presets for different circumstances: recommended colours, classic f.lux, working late, far from equator. Windows Night Light has a single warmth slider.
- Gamer monitors with variable refresh: both tools play nicely with G-Sync and FreeSync. You may see a brief flash when warmth changes; that is expected.
- Multi-monitor setups: both apply across all monitors. If one monitor is colour-calibrated for work, f.lux can exempt applications on it; Night Light cannot.
On mobile: iOS, Android, and the jailbreak question
Mobile current state
- iOS: Night Shift is built in. Settings, Display and Brightness, Night Shift. Schedule it sunset-to-sunrise. A separate feature called Color Filters (Settings, Accessibility, Display Accommodations) can push red even further for an even warmer display if you need it. f.lux is not available on non-jailbroken iOS.
- Android: Most Android versions have a Night Light feature in Settings, Display, Night Light. Vendor skins (Samsung One UI, OnePlus OxygenOS, Google Pixel) all implement it. Third-party apps like Twilight offer more granular control; f.lux has an Android preview but is not the strongest choice there.
- eInk devices (Kobo, Kindle): already warm by default, often with their own ComfortLight that shifts warmer after sunset. No f.lux needed.
- Older devices without built-in support: third-party apps like Twilight for Android or CareUEyes for Windows can fill the gap.
If you want to layer the effect, a pair of blue-blocking glasses stacked over a warmed screen gives you more melatonin protection than either alone. Our honest blue-light blocker review walks through what to look for in the glasses side.
Linux, eReaders, and the bigger screen-warming picture
Linux users: f.lux has a Linux build, but most distributions include Redshift or Gammastep in their default repositories, both of which work well and integrate with system schedulers. Settings vary by desktop environment; GNOME has built-in Night Light under Settings, Displays since 2017.
TVs and monitors are often overlooked. Many modern televisions have a "bedtime" or "low blue light" picture mode that warms the screen without software. Gaming monitors increasingly ship with Eye-Saver or Low Blue Light presets. Check your hardware menu before installing another tool. Also consider that warm household lamps matter more than warm screens for most bedrooms; 2700 kelvin bulbs do more ambient good than any software does for a single screen.
Does any of this actually matter for sleep?
Honest answer: a bit, not a lot. Screen warming is a small part of evening sleep hygiene. The much bigger levers are your mattress and pillow, your bedroom temperature, and how late you use screens at all.
What we tell Brantford customers
Customers ask us about screen-dimming tools more than they used to. The honest advice has not changed in 37 years of helping Brantford families sleep better. Turn on whichever tool is native to your device. Spend the saved decision energy on things that make a bigger difference. Side sleepers with neck tension sleep measurably better with a contour pillow like the Somnia 4.5 contour pillow. Hot sleepers who overheat at night gain more from a Cool Ice gel memory foam pillow than from any screen setting. For adults whose body position is the actual issue (reflux, hip surgery, chronic back pain), an Affordable Adjustable bed does more than a thousand hours of f.lux. Visit us at 441 1/2 West Street and we will help you figure out what is actually going on.
For the full evening wind-down routine that screen-warming fits into, our dopamine menu wind-down routine is the bigger habit. Our sleep environment checklist for Canada covers temperature, light, and humidity together.
Frequently asked questions
Is f.lux still relevant in 2026?
Less relevant than it was before 2017, more relevant than some would suggest. For most users, the native Night Shift, Night Light, or Android Night Light is enough. For users who want maximum blue-light reduction, per-app exceptions, or finer scheduling control, f.lux still wins on macOS and Windows.
Can I use f.lux and Night Shift at the same time?
Not recommended. They can conflict, producing unpredictable colour. Pick one. For most users, the native OS option is simpler and good enough. If you want f.lux, disable the built-in tool first.
Does screen warming actually help me sleep?
Modestly. A 2025 Frontiers in Neurology meta-analysis on evening blue-light management found mixed, small improvements in sleep onset and quality. The effect is larger for shift workers and evening screen-heavy jobs than for casual evening browsing. Pair with other sleep-hygiene habits for more meaningful gains.
Will warming the screen hurt my creative work?
Yes, if colour matters. Photos, design, video colour grading all look wrong on a warmed screen. f.lux handles this by letting you exempt specific applications. Night Shift and Windows Night Light do not. If you are a creative working at night, f.lux is the practical pick.
Does Mattress Miracle sell screen-dimming software?
No, we are a family-owned mattress and bedding store in Brantford. The tools we recommend here are free. Visit us at 441 1/2 West Street for the mattress, pillow, and bedding that your screen habits sit around.
Related reading
- Blue-light blockers evidence review
- Dawn alarms and Canadian winter sleep
- Dopamine menu wind-down routine
- Sleep environment checklist for Canada
- Circadian rhythm science guide
Visit our Brantford showroom
Mattress Miracle
441 1/2 West Street, Brantford, Ontario
Phone: (519) 770-0001
Hours: Mon to Wed 10 to 6, Thu to Fri 10 to 7, Sat 10 to 5, Sun 12 to 4
Your f.lux is set up right but sleep still feels off? The issue is almost certainly the mattress, pillow, or bedroom temperature. Come by and we will tell you honestly what needs fixing. Family-owned since 1997.