Healthy Eyes
Sundown removes screen flicker and the harsh blue light, so your eyes get a steady, calm screen all evening.
Software for a
healthier screen.
Block blue light and remove screen flicker on your Mac, so you can feel better, think clearer and sleep deeper.
Bring the sunset to your screen.
Sundown makes you love your screen again. Remove flicker and harsh blue light today.
Sundown
Warmth6500K
Brightness100%
“Wherever you are, be all there.” — Jim Elliot
Sundown is loved.
Sundown is a blue light blocking app for your computer. It filters blue light and removes screen flickering. This is why people love Sundown.
Start protecting your eyes tonight.
7-day free trial on monthly and annual. Cancel anytime.
Monthly$4.99/mo7-day free trial, then billed monthlyBlocks blue light, down to 500K deep redFlicker-Free Mode and Anti-DitheringEight presets and your own scheduleCancel anytimeStart Free Trial
MOST POPULARAnnual$39/year7-day free trialEverything in MonthlySave 34% against monthlyPriority supportEarly access to new featuresStart Free Trial
BEST VALUELifetime$79 oncePay once, own it foreverEverything in AnnualWorks on 2 computersLifetime updatesNo recurring chargesFounding memberBuy Lifetime
Your screen shouldn't ruin your sleep.
Blue light after sunset suppresses melatonin and disrupts your circadian rhythm.
Eye Strain
Screen light is unnatural and harsh. Its blue spike and hidden flicker tire your eyes fast.
Poor Sleep
Blue light at night limits melatonin production and harms your sleep quality. (Ostrin 2017)
Broken Body Clock
Evening blue light tells your body it is still daytime, so the signal to wind down never comes.
Try Free for 7 Days
7-day free trial · Cancel anytime before you're charged
The app for better focus and deeper sleep.
Your screen shouldn't hurt your focus, sleep, and performance. Sundown takes the blue light and the flicker out of your screen.
Work late.
Sleep like you didn't.
Your screen floods you with blue light every evening. Night Shift barely dims it. Sundown goes to 500K. Real circadian protection that lets you work without the damage.
1
Install
Download. Drag to Applications. Done in under 3 minutes.
2
Set your warmth
One slider. From gentle amber to deep crimson. You choose how deep.
3
Forget about it
Pick a preset once. Sundown holds your warmth until you change it.
Sundown makes your screen healthier.
Sundown makes your screen healthy by removing harsh blue light, so your eyes can relax, you can enter flow state, and sleep deep. It also blocks invisible flicker that tires your eyes and stresses your nervous system.
Filtered Blue Light
Sundown eliminates blue light, all the way down to a deep 500K red.
Flicker-Free Screen
Sundown removes screen flicker, so your display stays steady all evening.
Natural Scheduling
Your screen warms step by step through the evening, on its own.
Smooth Natural Display
Anti-Dithering turns down pixel shimmer, so the picture looks smooth and natural.
Lives in Your Menu Bar
One click opens your warmth and presets, with no account to make.
Simple Presets
Eight one-tap presets, from Energy at 6000K to Midnight at 500K.
Sundown is the number one app to filter all blue light and remove screen flicker.
Not all screen filters protect your biology. Here's the difference between dimming your screen and actually protecting your circadian rhythm.
| Feature | Sundown | Night Shift | f.lux | Iris |
|---|---|---|---|---|
| Deepest Kelvin | 500K | 2700K | 1200K | 1200K |
| Anti-Dithering | ✅ | ❌ | ❌ | ❌ |
| Custom Presets | 8 Kelvin presets | 1 slider | 3 modes | 9 presets |
| Scheduling | Custom | Basic | ✅ | ✅ |
| macOS Native ARM | ✅ Native | Built-in | Universal | x86 (Rosetta) |
| Tracking | None | Apple | Minimal | Google Analytics |
| Price | From $4.99/mo | Free (personal) | Free (personal) | From $4.99/mo |
Night Shift stops at roughly 2700K. Sundown reaches 500K.
Side by side in detail: Sundown vs Night Shift · Sundown vs f.lux · Sundown vs Iris
So much better than f.lux
Cameron Cruz
“So much better than f.lux. This is what I've been looking for.”
Actually life changing
Nat Larcos
“I've been obsessed with Sundown! Actually life changing. I need to start sharing it. Finally creating content again.”
Sundown is sick
James
“Sundown is sick. Shared it with a couple of my buddies as well. Word of mouth is the best marketing.”
So easy to use
Lucas Graham
“brilliant so easy to use super practical couldn’t of made it any easier to be able to implement and set up as well”
Sundown is the real deal
Matt Maruca
“As someone who’s built a company around circadian health, Sundown is the real deal. Nothing else comes close on software.”
The warm glow is so cozy
Ruby Rojas
“ok so I started using this because I read about blue light aging your skin and now I genuinely look forward to working on my laptop at night? the warm glow is so cozy. my whole evening routine feels different.”
Simple as that
Christian LeBlanc
“I spend 10+ hours a day editing video on my Mac. Sundown runs in the background and I genuinely sleep better. Simple as that.”
Whatever it is, it works
Jasmine
“I used to get headaches every single night around 9pm. Like clockwork. Installed Sundown two weeks ago and they just stopped. I think it’s the flicker thing? whatever it is, it works.”
My favorite app on my entire Mac
Jianna Capri
“this is my favorite app on my entire mac and i’m not even exaggerating. the warm screen at night is so nice. i’ve gotten like four of my friends to download it.”
FREE GUIDE
22 Tips For Better
Sleep & Performance
Short, practical tips on sleep, your circadian rhythm and what lighting research says, each with its source.
Circadian technology is evolving.
The frontier science on the impact of light on our health is moving fast, and it keeps changing how we think about the screens we look at every night. These are the guides we wrote from what we have learned so far.
Best Blue Light App for Mac in 2026
A comprehensive comparison of every blue light filter available for macOS.
The Science of Display Dithering
Why Apple Silicon gamma curves cause visible banding and how to fix it.
f.lux Alternative for Mac
Why biohackers are switching from f.lux to deeper circadian protection.
More from the blog
For the studies themselves, read our Screen flicker and eye strain research.
What people ask before they try Sundown
How is Sundown different from Night Shift?+
Night Shift maxes out at 2700K — a mild warm orange. Sundown goes to 500K — deep red. Harvard researchers found evening blue light delays your circadian clock by 3 hours — twice as long as comparable green light (Lockley, Brainard & Czeisler, 2003). Sundown is built for people who take that seriously.
Does Sundown track me?+
No. Zero analytics, zero telemetry. Sundown runs entirely on your Mac. No accounts, no cloud sync. Your screen settings are your business.
Will this actually improve my sleep?+
Research shows that properly blocking blue light before bed produces ~58% more melatonin and ~24 min longer sleep (Ostrin 2017). Sundown reaches 500K — far deeper than Night Shift's roughly 2700K floor.
Which macOS versions does Sundown run on?+
- macOS 26 Tahoe — Sundown
- macOS 15 Sequoia — Sundown
- macOS 14 Sonoma — Sundown
- macOS 13 Ventura — Sundown Classic
- macOS 12 Monterey — Sundown Classic
Apple Silicon and Intel Macs.
We're constantly updating which versions of macOS Sundown runs on. If it doesn't work on yours, please email us at support@trysundown.com.
Does Sundown stop screen flicker?+
Yes. Flicker-Free Mode keeps the backlight steady and dims through the color curve instead, for a flicker-free display. The Flicker-Free Mode guide explains how it works, and our research on screen flicker and eye strain covers the science behind it.
What is anti-dithering, and do I need it?+
Apple Silicon Macs use temporal dithering, which shifts pixel values very quickly to show colors the panel cannot show directly. Sundown's Anti-Dithering setting turns that down so color holds still. Some people notice dithering and some never do, which is why it is a setting you choose. The science of display dithering goes deeper.
How is Sundown different from f.lux?+
f.lux still ships: its Windows build is dated 8 April 2026. The Mac build hasn't changed since 17 May 2023. Its warmest setting is 1200K, and Sundown goes to 500K, with Flicker-Free Mode and Anti-Dithering built in. The full side by side is on Sundown vs f.lux.
Does Sundown work on Windows?+
Yes, there's an early version for 64-bit Windows 10 and 11. It has the warmth presets and runs from the notification area, and the plans and prices are the same as on the Mac. Everything it does today is on the Sundown for Windows page.
Can I use Sundown on two computers?+
With Lifetime, yes: it works on 2 computers. Monthly and Annual cover one computer. Got a new Mac? Email support@trysundown.com and we'll move your license over (terms).
Can I get a refund?+
If Sundown isn't working out for you, email support@trysundown.com and tell us what happened. We handle refund requests case by case and we aim to be fair about it. The details are in our terms.
Loved by people who take their sleep seriously.
Creators, founders and people who work late on a Mac, in their own words, about what changed once Sundown was part of their evening.
“So much better than f.lux. This is what I've been looking for.”
Cameron Cruz
@cameroncruz
“I've been obsessed with Sundown! Actually life changing. I need to start sharing it. Finally creating content again.”
Nat Larcos
@natlarcos
“Sundown is sick. Shared it with a couple of my buddies as well. Word of mouth is the best marketing.”
James
@sonofjvmes
“As someone who’s built a company around circadian health, Sundown is the real deal. Nothing else comes close on software.”
“ok so I started using this because I read about blue light aging your skin and now I genuinely look forward to working on my laptop at night? the warm glow is so cozy. my whole evening routine feels different.”
Ruby Rojas
@itsrubyrojas
“I spend 10+ hours a day editing video on my Mac. Sundown runs in the background and I genuinely sleep better. Simple as that.”
Christian LeBlanc
@lostleblanc
“brilliant so easy to use super practical couldn’t of made it any easier to be able to implement and set up as well”
Lucas Graham
@livelikelucass
“I used to get headaches every single night around 9pm. Like clockwork. Installed Sundown two weeks ago and they just stopped. I think it’s the flicker thing? whatever it is, it works.”
Jasmine
@jasminegabs
“this is my favorite app on my entire mac and i’m not even exaggerating. the warm screen at night is so nice. i’ve gotten like four of my friends to download it.”
Jianna Capri
@jiannacapri
The frontier science on light and its impact on humans
Light is the strongest signal your body clock gets, and science is only beginning to map what it does to us. The eye's own clock sensor was discovered in 2002. Much of the research on screens and sleep has been published in the last fifteen years.
We're building Sundown at that frontier. We read the research, publish what we find with every source linked, and say plainly where the evidence is still thin.
