In a Five-City iPhone Speed Test, AT&T Tops Verizon

Last month I conducted a tech test that made me consider something I never thought I would contemplate, after a few years of horrible service in the iPhone’s early days: Switching back to AT&T from Verizon.

When it comes to broadband, speed matters. And that’s especially true for cellular broadband, since the smartphone is, for many people, their principal digital data device. Speedy cellular data connections make it easy to watch YouTube and Netflix, stream music, download large files and photos, and more.

Slow connections can drive you crazy.

So every once in a while I do an informal, unscientific cellular data speed test, focusing primarily on downstream speeds over LTE, the current standard for fast cellular data (also known as 4G). My latest was a 12-day, five-city matchup last month, on both coasts, between the country’s two wireless giants, Verizon Wireless and AT&T.

And the winner was … AT&T, by a strong overall average of 22 percent. Using identical iPhone 6 phones, and the popular Ookla Speed Test app, I found that AT&T averaged 15.89 megabits per second in download speed, and Verizon lagged with an average of 12.99 Mbps.

In all my years of doing these tests, AT&T had only topped Verizon once before, in November 2013, and that was because of a ridiculously fast performance at one single spot in New York City.

This time, AT&T cleanly beat Verizon in four out of my five test locations: The Boston suburb of Medford, and three places in California — San Francisco, the Los Angeles Airport, and a resort hotel in Dana Point, between San Diego and LA. Verizon’s only win came in tests in and around my home base of Washington, D.C.

The test results weren’t all bad news for Verizon. It beat AT&T overall in upload speeds by more than 30 percent, at 7.8 Mbps versus 5.9 Mbps. And upload speeds are increasingly important, as people post videos and rich photos from their phones, and send business documents.

Verizon’s overall average speeds were better than its modest publicly promised speeds, left unchanged since it rolled out its LTE network in 2010. Those are 5-12 Mbps down and 2-5 Mbps up. AT&T says it doesn’t have a promised speed range.

I want to stress that this was a limited, nontechnical test, with only about 42 readings overall. Both networks’ average download speeds were well above what’s recommended for viewing most videos by Netflix and YouTube.

Here’s how I did my tests. In each location, at the same exact spot, and within the same few minutes, I ran the Ookla speed test app at least five times on each iPhone, then averaged the results. In the D.C. area, I did this in multiple spots in the city and suburbs. Then I averaged all the individual results to get the overall average speeds.

In general, AT&T’s performance was more consistent. Its average downstream speeds in the five locations ranged between 10 Mbps in downtown San Francisco and 29 Mbps in the Boston suburbs.

By contrast, while Verizon’s average also topped 20 Mbps near Boston, it averaged a pathetic low of only about 1 Mbps at a Virgin America gate at the LA airport (AT&T’s average there was over 11 Mbps). And in the southern California resort and downtown San Francisco, it came in at under 10 Mbps.

So it’s clear to me that — at least in my testing — Verizon is slipping. It was once the king of LTE, and the king of cellular speed. It was the first to widely deploy LTE, and still claims the largest network, covering more territory. And for years it delivered easily the fastest cellular data speeds to its customers.

In addition to its possibly flukey loss in my 2013 faceoff, Verizon got edged out by T-Mobile in a smaller, shorter test I performed last summer.

Meanwhile, AT&T is advancing. Its network coverage map is closing in on Verizon’s. And its performance — both in data and voice — has improved mightily since the dark days when it was the exclusive carrier for the then-new iPhone and its network buckled under the strain.

When I told Verizon about my test results, a spokeswoman noted that my test wasn’t comprehensive, adding: “It’s all about a consistent, reliable experience.” She said Verizon isn’t currently claiming to be the fastest network, though some test labs have claimed it is.

AT&T, not surprisingly, was pleased by my results, but it also isn’t touting speed per se, as much as something it calls “the nation’s strongest LTE signal.” The company says that means the ability to keep a steady, good signal, but it sounds like marketing-speak to me.

It wasn’t all that long ago that AT&T’s cellular service was the butt of many jokes — but that was more about dropped voice calls than data. While my tests weren’t focused on voice calls, neither network dropped any during my test period. And streaming video, email and Web surfing worked okay on both, though in some places they were discernibly slower on the Verizon iPhone.

Your mileage may vary, of course. The performance of cellular networks can be impacted by phone model, time of day, precise location and network congestion.

And you may find better and more consistent performance with one of the two smaller carriers, Sprint and T-Mobile, which I chose to omit from this latest test, but have tested in the past.

When AT&T’s exclusivity deal for the iPhone ended in 2010, I jumped to Verizon as soon as I could. Next time, I just might go back.

This article originally appeared on Recode.net.