How Private Is My Sensor?

Many members of the PurpleAir community have understandable concerns about personal privacy. Often, these concerns lead individuals to avoid registering their sensors with us. This is a perfectly valid option for PurpleAir users. However, there are also many ways to reinforce privacy when registering.

Here are a few things to consider:

  • Registered Name
  • Registered Location
  • Public vs Private Registration

Naming Your Sensor

During the registration process, you are asked to give your sensor a “Location Name.” This is the name of your sensor. There are no restrictions or requirements associated with naming. Frequently, our users will use their address or street as the name, but you do not have to name it this way. We recommend choosing a name that is something you know, but doesn’t specifically identify you or where you live.

Screenshot 2023-09-15 at 2.58.02 PM

Choosing A Location

When registering, you have the option of including a sensor location. If you do, you use a Google Maps pin to indicate where the sensor is located. PurpleAir devices do not have internal hardware that tracks location, all pins indicated on the map have had their locations chosen by their owners.

Screenshot 2023-09-15 at 2.58.51 PM

Public sensors that have not been given a location during registration are displayed in what we call “No Man’s Land.” More information can be found in this community article.

For anonymity reasons, you do not have to place the pin directly on your house or home. We recommend registering the location as somewhere adjacent to your home, such as in the middle of the street. That way, no house can be specifically identified. As long as the registered location is reasonably close to the sensor’s physical location, the data quality will not be dimished.

Registering As Public Or Private

Screenshot 2023-09-15 at 2.58.18 PM

The last thing you have to consider is marking your sensor as public or private. The main difference between the two is map visibility and data availability. A public sensor will appear on the map for all users. Historical data can be freely pulled from the API for any public sensor, so researchers may retrieve the data from the sensor to be used in studies.

A private sensor, on the other hand, will only be visible to the owner of the sensor and anyone that the owner shares the appropriate information with. Private sensor data is only available from the API if the user supplies the correct identifying information (the same private information required to view the sensor on the map).

Data from private sensors and public sensors is stored on separate servers. This is to ensure data privacy and security.

Learn More

Viewing Your Sensor On The Map
Map Startup Guide
View Local Sensor Output Over Wifi


Hello. In the privacy policy it says that you can opt out of use of location information by Purple Air “by changing your geo-location settings consistent with our device protocol”. I have a few questions:

  • Can you please confirm that this includes any information Purple Air collects from Google Geolocation API
  • Where are the “geo-location settings consistent with our device protocol”? At registration I cannot see anything about the device protocol that would tell Purple Air not to use locational information of any kind, just that I can elect not to provide my own geolocation information.
  • Does failure to allow geo-location information of any kind affect anything else about the access to information from the senor?

Hi @purpleairau

When a sensor performs a Google Geolocation lookup, PurpleAir will receive that information. If you register your sensor and/or connect it to WiFi, it will perform a Google Geolocation lookup. However, that information is never shared with any other parties, whether you provide a location or not. The only indicator of this information that can be found on the map is the geolocation star rating, which will display as zero if you do not provide a location.

You can decline to provide a location during registration by leaving the Set a location on the map box unchecked. Declining to provide location information will not affect your access to the sensor’s data. You will still be able to view its readings and collect information from the API.