Sundown vs Iris for Mac (2026): What Happened to Iris and What to Use Now
By Jack RichardsFounder, Sundown
PWM flicker at low brightness is linked to headaches in sensitive people.
Iris's macOS release history is harder to read. The website still sells it and the download still works, but you can't easily tell how recent the macOS build is.
Iris got important things right, so this comparison is meant as a fair look at what Iris offered, what it left unfinished, and where Sundown picks up.
Quick Answer: Sundown vs Iris
Iris's downloads are behind JavaScript and it publishes no macOS build date, so we couldn't confirm when it last shipped. Sundown is actively maintained, goes down to a deep red, and includes anti-dithering for Apple Silicon displays.
The Full Comparison Table
The Sundown column describes the current build, and the Iris column sticks to what we could check.
| Feature | Sundown | Iris |
|---|---|---|
| PWM flicker mode | Flicker-Free Mode (built-in display: backlight at full, dims through the gamma table) | Has had a PWM-related mode |
| Break timer (20-20-20) | No | Yes |
| Presets | Seven warmth presets plus a Custom one | Multiple modes (Health, Reading, etc.) |
| Last Mac update | Actively maintained | Not published, downloads are JS-gated |
Two things jump out. The first is depth, since Sundown goes down to a deep red. The second is upkeep (see the quick answer above).
What Iris Got Right (and Why It Mattered)
Iris was early to two ideas.
PWM flicker protection. When you dim an LCD display, the backlight doesn't get dimmer in a continuous way. It flashes on and off faster than you can see, which is called pulse-width modulation, and at lower brightness the off-periods get longer. Some people perceive this as flicker, with headaches, eye strain or nausea. Iris took this seriously early in the consumer app space and has offered a PWM-related brightness mode.
If you've ever wondered why your eyes hurt more at low brightness than at full brightness, PWM flicker is one possible reason, and Iris saw that early.
Break timers. The 20-20-20 rule (every 20 minutes, look at something 20 feet away for 20 seconds) is recommended by the American Academy of Ophthalmology. Iris built the reminders straight into the app.
Where Iris Fell Short
There are two differences you can check on your own Mac today.
No anti-dithering. Apple Silicon displays use temporal dithering to simulate color depth, which means the display rapidly alternates between two nearby colors to create the illusion of a shade in between. At warm color temperatures this produces a subtle shimmer. As far as we could find, Iris doesn't offer an anti-dithering mode. Sundown's anti-dithering mode was built specifically for them.
How warm it goes. The research on evening light keeps pointing one way, which is that after dark, less short-wavelength light is better. Sundown goes down to a deep red.
Migrating from Iris to Sundown
If you're one of the people still running Iris, here's how to switch:
- Quit Iris (menu bar → Quit, or force-quit if it's hanging)
- Delete Iris from Applications (drag to Trash, then empty the Trash)
- Download Sundown from trysundown.com
- Open Sundown, which sits in your menu bar
- Click the menu bar icon and drag the Warmth slider to the right, toward red; at the far right it reaches a deep red, the warmest step on the warmth ladder
If you used Iris's break timer, Sundown does not have one, so a phone timer or a free break app can handle the reminder.
What About Iris Mini?
Iris also offered a "mini" version, a stripped-down blue light filter without the break timers, modes, and settings complexity.
Sundown goes down to a deep red and includes a Flicker-Free Mode that dims through the gamma table instead of the backlight.
Why Not Just Use Night Shift or f.lux Instead?
If you're leaving Iris, it's fair to wonder about the free options.
Whichever you pick, the reason to warm your screen at night is the same, and the research behind it (with its limits) is on the Sundown science page.
Night Shift stops at a warm white.
f.lux goes to a deep orange at its warmest preset, and we compare it in detail here. If you're leaving Iris over its unpublished macOS cadence, note that f.lux still ships: its Windows build is dated 8 April 2026. The Mac build hasn't changed since 17 May 2023.
The full breakdown is in our best blue light app comparison, which covers every option side by side.
FAQ
Is Iris still safe to use on a current Mac?
We can't give you a clean answer, and that's the real problem. Iris doesn't publish a macOS build date (its downloads are JavaScript-gated), so there's no way to see what it has been patched against. If you rely on it, check with Iris directly before your next macOS upgrade.
How can I tell whether Iris is still maintained?
Look for a published macOS build date or release notes. When we checked for this comparison, Iris's downloads were JavaScript-gated and no macOS build date was published. Sundown changes your display color through macOS display APIs.
Can I get a refund from Iris?
If you bought Iris recently, contact iristech.co support, and if you bought it through the Mac App Store, Apple's refund process applies.
What color temperature should former Iris users start with on Sundown?
Start around a deep orange, and after a few nights try a deep red.
Feel the difference tonight. Start your 7-day free trial and see what a deep red screen looks like after dark.
