How does M-Lab identify the locations of tests? How precise is the location information?

When exploring or aggregating M-Lab test data by geography, it’s important to understand the limits of geographic precision in our public data when using BigQuery. Because M-Lab provides open, publicly available datasets, we limit the location accuracy of test results out of respect for user privacy. Our Privacy Policy provides comprehensive details on the information M-Lab collects.

When you run an M-Lab test, in addition to providing you with a measurement, we collect the IP address assigned to your cable modem, router, etc. by your ISP. By looking up the IP address in a publicly available dataset, we “annotate” each test result with geographic fields like latitude and longitude coordinates, continent, country, city, and postal code. IP address geolocation is not the same as a street address or GPS location. M-Lab recommends that our public data be considered precise to the city or county/region level.

Because we are an open platform, third parties may develop custom integrations of  our tests in their websites, software, or hardware. These tests still test to the M-Lab platform but may provide additional features to the communities that use them. Some third party integrations of M-Lab test clients may ask you for additional information through a survey, or your location to enhance the geographic specificity of your test result. If you supply your location or other information, it will not be collected by M-Lab. The third party maintaining the integration of our test is responsible for maintaining the privacy of this data, and comply with M-Lab's Acceptable Use and Privacy Policies. M-Lab lists known integrations of our tests on our Data Tools page.