Dark Sky Meter
Helps you measure the night sky brightness

The Award winning Dark Sky Meter by DDQ helps you measure the night sky brightness with the press of a button.
Get instant information about the night sky quality and contribute to create a global map of sky darkness.
Featured on BBC Television, CBS.com, Scientific American, Scistarter and many more influential websites and magazines.
At a fraction of the cost of a commercial Sky Quality Meter.
Available for download now!

User comment: Fantastic! Settling the argument with my observing friends over which of our sites is better is worth the $5 all by itself. And if I win the wager for a beer, it will be like getting the app for free.
Jeff Morgan, Prescott AZ

Download the app here!


Where does the data go?

All of our data is delivered to the Globe At Night project. Your measurements are used by scientists to create new light pollution maps, do research and raise awareness. Data is collected anonymously and you never have to leave your personal data.

Does the app work from a remote location without internet?

Yes it will, you can measure from everywhere, but make sure that you open the app and keep it open for a few minutes with an internet connection.

Why isn’t this app free?

No, the app isn’t free. The app costs $0.99 to cover the hosting costs. I’m doing this to contribute the awareness for dark skies, not to make any profit.

What is the best way to measure?

– Always aim at the Zenith (the point right above your head)

– Make sure its dark. You can use the info panel.

– Perform a measurement when the moon is not visible.

– Take a good dark by covering the camera! A good reading always starts with taking a dark. Put the iPhone in your pocket and cover it.



Dark Sky Meter calibration setting (expert mode)

This setting is for people who own a unihedron SQM or SQM-L.
If you own a unihedron SQM the calibration on the iPhone can be adjusted to the outcome of the Unihedron
Sky Quality Meter. The SQM uses dedicated hardware and is known as the ‘gold standard’.

You can roughly calibrate the app using the unihedron sqm. iPhones can differ slightly (but constantly). It is best to take a series of measurements using both devices.


If the SQM shows 20.30 and your iPhone shows 20.15 you can put .15 in the 20.00 and up field.
If the SQM shows 20.15 and your iPhone shows 20.13 you can put -.15 in the 20.00 and up field.

Same goes for measurements with sqm 20 or lower, then you should use the 10.0>20.0

Will there be an android version?

There are a lot of different Android devices, more than 4000 in total (2013). With so many camera types on the market, it will be impossible to make a decent Android port of our software. Adapting our software to all camera’s will be impossible or cost a fortune.

Will the app work on iPhone 6, SE and higher?

Yes, the app will work. But we are still in the testing phase.

Is the map on the darkskymeter.com website live?

No, it isn’t.

The map on the site is updated 3 -4 times a week. We’ll check the data first before it is shown on the map. In 2014, we’ll try to automate it.

The map in the app is always live if you have an internet connection ready.


Will the app work on iPad?

No. The camera’s are poor in low light conditions. There’s no workaround for it.

What does the seeing value mean ?

The DSM weather panel gets is data from the 7timer API. A high value indicates a poor seeeing. Here’s how it translates.

1 <0.5" 2 0.5"-0.75" 3 0.75"-1" 4 1"-1.25" 5 1.25"-1.5" 6 1.5"-2" 7 2"-2.5" 8 >2.5″