The third-largest carrier had the fastest network on average for downloading data in the fourth quarter, according to research firm OpenSignal, which measures mobile data speeds via an app test used by hundreds of thousands of ordinary consumers. Nationally, T-Mobile customers who used the test had an average download speed of 21.1 megabits per second on 4G connections, followed by Verizon at 20.9 Mbps. AT&T was third at 17.8 Mbps and Sprint trailed at 13.9 Mbps.

The averages for all four carriers were slightly better than in 2017.

The top two download speed results were close enough that OpenSignal said the difference was not statistically significant. The firm called the race a draw between Verizon and T-Mobile and praised Verizon for improving its network. T-Mobile was the clear winner a year earlier.

“Boosted speeds, extended LTE reach and improved video quality have sent Verizon to the top of most of our metric categories and has left Verizon and T-Mobile duking it out for our Download Speed Experience award,” the firm wrote in its report. “Make no mistake, T-Mobile isn’t down for the count. In every metric Verizon won, T-Mobile is a very close second in our analysis, and will likely contest each of Verizon’s current wins in our future U.S. reports.”

The tight race and industry-wide improvements come about two years after all four carriers brought back affordable unlimited data plans, slashing costs for consumers who were using ever more megabits to watch YouTube videos and upload Instagram pictures but challenging network capacity to keep up. Competition waned somewhat in 2018, as the carriers spent big to improve their networks and raised prices on some users by introducing pricier premium unlimited plans.

In the OpenSignal report, Verizon (VZ) passed T-Mobile (TMUS) for top position as having the most available 4G network. Its customers were able to get a 4G connection 94.2% of the time, ahead of T-Mobile customers at 94%, AT&T at 88.9% and Sprint at 88.4%. T-Mobile and Sprint (S) are still waiting to hear whether U.S. antitrust authorities will allow them to merge.

AT&T (T) had the most responsive network in the tests. OpenSignal’s app measures latency, or the time it takes for a phone to request data from the network and get a response. AT&T customers’ average latency was 57.8 milliseconds, T-Mobile’s was 60.6, Verizon’s was 62.6, and Sprint’s was 70.

The crowd-sourced rankings from OpenSignal reflect the real world experiences of customers, unlike the more carefully planned and scheduled tests done by other firms. But that also means that the app-based tests may not be representative of the experience of the average customer at each carrier, either. Rootmetrics, which performs more formal, repeated tests, has put Verizon on top in the past.

OpenSignal said the conclusions in its latest report were derived from over 10 billion speed test measurements on more than 1.1 million mobile devices from Sept. 16 through Dec. 14, 2018.

Declaring Victory

After the report was released, T-Mobile, Verizon and Sprint all crowed about different parts of the results. AT&T didn’t comment.

Sprint pointed to its improvements along many metrics from the results a year earlier. “Nobody can deny that Sprint has made dramatic network improvements in the last few years, and our large Next-Gen Network investment is well under way to improve coverage, reliability and speed across the country,” the fourth-largest carrier said in a statement. “We’re pleased to see our overall averages up year-over-year, and we achieved a win over AT&T in Video Experience.”

Verizon declared victory, as the strength and breadth of its network has long been the top selling point of the largest carrier. “OpenSignal’s findings clearly show that Verizon has the best network experience, which covers everything from 4G LTE availability to video experience, not just speed,” the company said in a statement. “Even though we’ve clearly come out on top here though, we don’t just take the word of one test taken over a single quarter. Across six different studies last year with varying methodologies, Verizon is consistently found to have the best network.”

T-Mobile pointed to its neck and neck finish with Verizon in several categories. “The days of Verizon’s unchallenged network leadership are long gone,” T-Mobile chief technology officer Neville Ray said in a statement.

(This story was updated on January 24 with comments from Verizon, Sprint and T-Mobile.)