While both Verizon and AT&T claim to offer the best voice, SMS and data coverage, reviewers agree that Verizon edges out AT&T for the best overall coverage in the United States. Verizon takes the top spot because of its superior coverage in rural parts of the country.
Verizon offers coverage to 98 percent of U.S. residents, thanks to its 100 percent coverage in metro areas and 95 percent coverage in rural areas. AT&T, meanwhile, offers 100 percent coverage in urban areas and 75 percent in rural areas.
A 2014 RootMetrics study concluded Verizon beats all other mobile carriers for voice, SMS and data coverage in 35 out of 50 states and tied with AT&T in 10 others. The study found that Verizon offered the best general reliability, call quality and text messaging and data performance.
The RootMetrics study, the most comprehensive and unbiased study of its kind as of 2015, incorporated testing in all 50 states in 6,300 locations. It based its coverage ratings on both reliability and speed.
In December of 2015, PhoneArena.com conducted a mobile coverage study in which it found that Verizon offered the best 4G coverage and was the only wireless carrier offering an LTE-only 4G network. All other carriers at the time offered 4G HSPA+, which is considerably slower.