Turn your phone into a Sky Quality Meter

Dark Sky Meter measures the brightness of the night sky so you can track light pollution, find darker skies, and contribute to a global citizen-science database.

iPhone · iOS

Dark Sky Meter

The original. A simple, one-tap sky-brightness meter for iPhone. Great for stargazers, astronomers, and anyone curious about the night sky.

Download on the App Store

iPhone · iOS · Pro

Dark Sky Meter Pro

RAW sensor capture, calibration, per-measurement privacy controls, CSV export, and a public map. For serious users who want SQM-L-grade accuracy. Read the manual →

Download on the App Store

Android Experimental

Dark Sky Meter for Android

An experimental Android build of the Dark Sky Meter. Camera sensors vary widely on Android, so accuracy is still being validated — your feedback helps.

Get it on Google Play

Android

Loss of the Night

A citizen-science app for Android. Report how many stars you can see, no camera required — your observations feed directly into light-pollution research.

Get it on Google Play

Why measure?

80% of people in North America can no longer see the Milky Way.
Light pollution disrupts wildlife, human sleep, and wastes billions in energy each year.
Your measurements feed into an open global map that researchers, planners, and advocates use.
Every data point helps identify trends and protect the last remaining dark sky places.

See the public measurement map →