Best Cell Phone Coverage – Maps Compared

Summary

All three of the nationwide cellular networks cover the large majority of Americans. Verizon is the clear winner in terms of overall network reliability. AT&T comes in second place. While T-Mobile has the smallest coverage profile, the network still has a strong presence in most well-populated areas.

Each of the major network operators shares an interactive coverage map on its website:

• Verizon’s map
• AT&T’s map
• T-Mobile’s map

Comparing Maps

I pulled snapshots of maps from each of the major networks’ websites.¹ Here’s Verizon’s map:

Now AT&T’s map:

And finally T-Mobile’s map:

A few things become apparent when comparing the coverage maps:

• T-Mobile has the smallest coverage profile.
• All three networks cover most Americans.
• All three networks almost always cover densely populated areas.
• The western U.S. has spottier coverage than the rest of the U.S.

Misleading maps

Coverage maps are often misleading. It’s not just an issue caused by shady marketers. Figuring out coverage is tricky. It’s not always clear cut whether a specific location has coverage. Factors like precipitation, humidity, and phone hardware can alter whether a signal is available in a particular spot.

Network operators have to make a lot of hard choices when building predictive models to estimate their coverage. There’s also a lot of flexibility in how coverage predictions get displayed. Comparing the maps above, you might think AT&T has the best coverage. However, it looks like AT&T smooths its nationwide map by hiding small areas lacking coverage.

Independent evaluations

Instead of taking maps at face value, it’s helpful to look at the results from independent companies that collect data on networks’ performance.² I’ve spent a lot of time digging into these companies’ methodologies and results. In my view, RootMetrics is in the best position for assessing network reliability at the national level.³

Here’s how the three networks scored for reliability at the national level in RootMetrics’ report for the second half of 2019:⁴

1. Verizon – 96.3
2. AT&T – 94.9
3. T-Mobile – 87.7

Choosing a network

Before choosing a network, I recommend checking out coverage at your own address using networks’ interactive maps. Here are those links one more time:

• Verizon
• AT&T
• T-Mobile

If you need great coverage, you should probably go with Verizon’s network. If you spend all your time in big cities, you might be able to save a few bucks by opting for a network with less impressive coverage.

Last updated: August 2020

1. Map snapshots were taken from the network operators’ websites on 8/5/2020.
2. By “independent”, I mean evaluators that are not owned by network operators. I don’t mean to imply that independent evaluators are impartial or free of conflicts of interest.
3. I believe RootMetrics’ methodology is particularly well-suited for assessing nationwide reliability. RootMetrics drives high-end phones connected to the major networks all around the country. During the drives, the phones conduct tests of network performance. The company’s testing has substantial geographic coverage, and RootMetrics’ nationwide results may be less prone to selection bias than other companies’ results.

   With crowdsourced data that many other companies rely on, I worry that users on some networks may be systematically different from users on other networks. Differences in network quality based on crowdsourced data could be due to either true differences in networks’ quality or differences in the behavior and location of users on each network.

   RootMetrics’ tests are pretty well-controlled. High-end devices are used, and phones conduct tests in the same locations at the same times. I go into more detail in my article on RootMetrics’ methodology.

4. Verizon didn’t just do well in the most recent reporting period. Verizon has taken the top overall ranking and the top network reliability ranking in every biannual period since at least the second half of 2013. (I’m unsure whether RootMetrics provided the same kind of rankings prior to 2013.)

   Unfortunately, RootMetrics is not transparent about how exactly it reaches its final scores or what exactly the scores mean. RootMetrics hides details about its methodology and allegedly uses a “proprietary algorithm.”