Wireless providers are extremely fond of arguing and fighting with each other as to who provides the fastest and most reliable service. That’s why reliable third-party testing, like that provided by OpenSignal, is so important for helping consumers figure out which service is actually the best.
At least, this is true in theory. In practice, it turns out that in terms of overall reliability, Verizon still wins in each individual region in the US. Speed is a little more split, with T-Mobile offering faster service in the Northeast and Southeast, while Verizon wins out in the Midwest and Northwest (the two tied for the Southwest).
Oh, and no matter where you live, Sprint is still the worst across the board. Sorry, Sprint customers.
OpenSignal’s methodology is particularly useful for determining reliability, as it sources data from "millions of smartphones” through its app, which tests and reports on signal strength. Although data could be skewed if the app isn’t on a representative sample of smartphones.