Premium
Download Twilight: Blue light filter 13.6 APK
Supports installation on external storage.
Target: Android 13 (API 33)
What's new in Twilight: Blue light filter 13.6
- Fix for watch sync with Wear OS 3+
- Targeting Android 13
- Not filtered screenshots on all Android versions + better status and navbar coloring
About Twilight: Blue light filter 13.6
Are you having trouble falling asleep? Are your kids hyperactive when playing with the tablet before bed time?
Are you using your smart phone or tablet in the late evening? Are you sensitive to light during migraine?
Twilight may be a solution for you!
Premium
Recent research suggests that exposure to blue light before sleep may distort your natural (circadian) rhythm and cause inability to fall asleep.
The cause is the photoreceptor in your eyes, called Melanopsin. This receptor is sensitive to a narrow band of blue light in the 460-480nm range which may suppress Melatonin production - a hormone responsible for your healthy sleep-wake cycles.
In experimental scientific studies it has been shown an average person reading on a tablet or smart phone for a couple of hours before bed time may find their sleep delayed by about an hour. See references below..
The Twilight app makes your device screen adapt to the time of the day. It filters the flux of blue light emitted by your phone or tablet after sunset and protects your eyes with a soft and pleasant red filter. The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times.
You can also use Twilight on your Wear OS device.
Documentation
twilight.urbandroid.org/doc/
Get more from Twilight
1) Bed reading: Twilight is more pleasant on the eyes for night reading. Especially as it is able to lower the screen backlight far below the ability of the backligt controls on your screen
2) AMOLED screens: We have tested Twilight on an AMOLED screen for 5 years without any sign of depletion or over-burning. If properly configured Twilight causes less light emission (by enabling dimming) with more equal light distribution (dark areas of the screen such as the status bar get tinted). This may in fact increase your AMOLED screen life time.
Basics on circadian rhythm and the role of melatonin
en.wikipedia.org/wiki/Melatonin
en.wikipedia.org/wiki/Melanopsin
en.wikipedia.org/wiki/Circadian_rhythms
en.wikipedia.org/wiki/Circadian_rhythm_disorder
Permissions
- location - to find out your current sunset/surise times
- running apps - to stop Twilight in selected apps
- write settings - to set back-light
- network - access smartlight (Philips HUE) to shield you household light from blue
Accessibility Service
In order to filter also your notifications and lock screen the app may ask for enabling Twilight Accessibility Service. The app uses this service only to better filter your screen and does not collect any personal information. Please read more about this at twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/
Automation (Tasker or other)
sites.google.com/site/twilight4android/automation
Related scientific research
Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans Derk-Jan Dijk, & Co 2012
Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans Joshua J. Gooley, Kyle Chamberlain, Kurt A. Smith & Co, 2011
Effect of Light on Human Circadian Physiology Jeanne F. Duffy, Charles A. Czeisler 2009
Efficacy of a single sequence of intermittent bright light pulses for delaying circadian phase in humans Claude Gronfier, Kenneth P. Wright, & Co 2009
Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans Kenneth P. Wright, Claude Gronfier & Co 2009
The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work Nayantara Santhi & Co 2008
Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina Farhan H. Zaidi & Co, 2007
High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Lockley SW & Co. 2003
Twilight: Blue light filter 13.6 variants
This release comes in several variants (we currently have 2). Consult our handy FAQ to see which download is right for you.
Version:14.5
Uploaded:September 17, 2025 at 10:34AM UTC
File size:6.90 MB
Version:13.8(524) for Android 4.1+ (Jelly Bean, API 16)
Uploaded:October 2, 2023 at 4:18PM UTC
File size:5.15 MB
Downloads:183
Version:13.7(519) for Android 4.1+ (Jelly Bean, API 16)
Uploaded:September 6, 2023 at 3:38PM UTC
File size:5.15 MB
Downloads:48
Version:13.6(515) for Android 4.1+ (Jelly Bean, API 16)
Uploaded:July 10, 2023 at 8:16PM UTC
File size:5.15 MB
Downloads:50
Version:14.25
Uploaded:February 9, 2026 at 12:04PM UTC
File size:10.66 MB
Downloads:458
Version:14.24
Uploaded:February 5, 2026 at 5:14PM UTC
File size:10.66 MB
Downloads:23
Version:14.22
Uploaded:January 22, 2026 at 6:14PM UTC
File size:10.71 MB
Downloads:40
Version:14.21
Uploaded:January 6, 2026 at 9:40AM UTC
File size:10.61 MB
Downloads:46
Version:14.20
Uploaded:December 18, 2025 at 6:55AM UTC
File size:10.61 MB
Downloads:338
Version:14.17
Uploaded:November 27, 2025 at 3:49PM UTC
File size:9.26 MB
Downloads:87
Version:14.15
Uploaded:November 26, 2025 at 6:46PM UTC
File size:9.99 MB
Downloads:103
Version:14.14
Uploaded:November 10, 2025 at 7:59AM UTC
File size:9.61 MB
Downloads:64
Version:14.10
Uploaded:September 24, 2025 at 1:34PM UTC
File size:9.25 MB
Downloads:132
Version:14.7
Uploaded:August 6, 2025 at 3:09PM UTC
File size:9.00 MB
Downloads:138
