Night Filter

Warm and dim your whole screen at night. It sits over every app you open, and it can't go online: no internet access, no ads, no tracking.

For Android 8 and later

Night, 3200 K

Your phone is the brightest, bluest light in a dark room

Screens are made to look like daylight, which suits noon and not 10 pm. Night Filter turns the whole screen warm and dim, like a lamp in the evening.

Bright, blue-rich light late in the evening can hold back melatonin, the hormone that tells your body it's night. Brightness counts as well as color, so Night Filter handles both: the color of the light, and a dim that goes below your phone's lowest brightness.

Already have Night Light?

If your phone's built-in night mode is all you need, keep using it. Night Filter began when Night Light and Extra dim, both on, still weren't warm enough or dark enough.

Warmer: Down to 1700 K, past candlelight. Android's standard Night Light stops around 2600 K.
Darker: Dim works on top of your lowest brightness, and on top of Extra dim if your phone has it, so it goes as dark as you need. Warmth and dim share one switch and one timer.
Gentler: The auto timer fades in over 20 minutes instead of switching over in seconds.
The same on every phone: Any phone with Android 8 or later, whoever made it.

Warm light, not an orange sheet

An app can't change how your screen makes color. All it can do is lay a window over everything: let part of the screen through, and add a color of its own.

A plain tinted layer paints orange on top, so black turns brown and the screen washes out. Night Filter works out the color of real light at the temperature you choose, then finds the window that turns white exactly that color while adding as little light as it can. Blue is only ever taken away, so blacks stay close to black and colors keep their relationships.

	White becomes	Black becomes
Another filter app	138, 123, 107	51, 36, 20
Night Filter	138, 123, 107	31, 16, 0

Measured on a Nothing Phone (4a) Pro, with both apps set to give the same white. Night Filter is at 3200 K, 43% intensity, 46% dim (it starts lighter, at 20% dim). Values are red, green and blue, out of 255.

The math

An overlay shows a share t of the screen plus a fixed veil of color. For a target white W (the color of a glowing body at your temperature, mixed by Intensity and scaled by Dim), the overlay that reaches W with the least veil is:

out  = t × screen + veil
t    = min(W)
veil = W − t

The blue channel sets t, so blue is scaled exactly as a real white-point shift would scale it, and the veil holds no blue at all. The color of each temperature comes from the CIE Planckian locus (Kim et al., 2002), converted to sRGB.

Light named after real light

Six presets, from a candle to a fluorescent tube, or anything from 1700 to 4500 K. Intensity and Dim are set separately, and Dim goes below your phone's lowest brightness, so it doubles as a screen dimmer for reading in bed.

It fades in, the way dusk does

Set your own start and end times. When the timer starts the filter, it doesn't snap on: it fades in over 20 minutes, and out again over 20 minutes in the morning. No location needed.

Turning it on or off yourself is instant.

No internet access. None.

Night Filter was built without Android's internet permission, so Android won't let it connect, even if we wanted it to.

It can't send anything over the internet: no ads, no analytics, no account, no crash reports. That matters for an app that sits over every app you open, from your messages to your bank to your two-factor codes. The popular filters we checked all show ads, go online, or both.

Six permissions, each with one job

Display over other apps SYSTEM_ALERT_WINDOW: Draws the filter over your apps.
Run in the foreground FOREGROUND_SERVICE: Keeps the filter on screen while it's on, with its notification.
Run in the foreground: special use FOREGROUND_SERVICE_SPECIAL_USE: The kind of foreground service Android 14 and later asks the app to name. Night Filter names it a screen color filter overlay.
Show notifications POST_NOTIFICATIONS: The notification with Pause and Turn off.
Run at startup RECEIVE_BOOT_COMPLETED: Turns the filter back on after a restart.
Google Play billing com.android.vending.BILLING: Buys Night Filter Pro through the Play Store app on your phone.

That's the whole list. The app's build fails if anything else ever appears in it.

Covering the status bar is optional, and draw-only

Out of the box, Night Filter tints your apps. To also cover the status bar, notification shade, quick settings and lock screen, turn on Cover status bar and notifications. Android only allows that through its Accessibility service, so Night Filter explains this and asks first.

The service draws the filter and does nothing else. It doesn't read your screen, doesn't see what you type, and can't tap or act for you. It isn't an accessibility tool, and you can turn it off at any time.

Your settings stay on this phone

Your settings are the only data Night Filter keeps. They stay on this phone and are left out of backups and device transfers. The privacy policy says the same, in full.

What you get

One tap and the sun sets
Night Filter

by Orionian

No ads, no tracking, no internet access.

No internet access, by design.
- Candlelight 1800 K
- Dawn 2000 K
- Incandescent 2700 K
- Night 3200 K
- Halogen 3400 K
- Fluorescent 4200 K
Light named after real light
Starts

22:00

Ends

07:00

Fades in and out over 20 minutes.

Fades in over 20 minutes

Six presets named after real lightCandlelight 1800 K, Dawn 2000 K, Incandescent 2700 K, Night 3200 K, Halogen 3400 K and Fluorescent 4200 K. Or anything from 1700 to 4500 K.
Intensity and Dim, set separatelyWith live preview. Dim goes below your phone's lowest brightness, so it doubles as a screen dimmer for reading in bed.
An auto timer that fadesYour own start and end times, fading in and out over 20 minutes, the way dusk does. No location needed.
Pause for a minuteFrom the notification. Like any overlay, the filter shows in screenshots, so pause it for a clean one or for true colors. It comes back on its own.
Quick Settings tile and home-screen widgetsTurn it on and off without opening the app.
Back after a restartIt comes back on after a restart or an app update.
Your taps pass straight throughThe filter sits over the screen, never in the way of what you touch.
Made for the darkA true-black interface built around one control: tap the setting sun. Sliders show the light they make and tick under your thumb.

Night Filter Pro

Everything above is free, for good. Pro adds four things for people who use Night Filter every night, as a one-time purchase in the app. It's what keeps Night Filter free of ads.

Wind downThrough the evening the light keeps warming, from your color to candlelight by the time you sleep.
Follow sunsetThe timer starts at sunset and ends at sunrise, every day. No location permission: it uses your time zone or a city you pick.
Your own presetsSave the color, intensity and dim you like, and switch with a tap.
Preset widgetYour presets as buttons on your home screen.

Get Night Filter

For Android 8 and later. iPhone doesn't let apps filter the whole screen, so there's no iOS version.

Night Filter is not a medical device. If you have trouble sleeping or with your eyes, talk to a doctor.