T-Mobile US has come top among US mobile operators in speeds tests by Open Signal and Ookla's Speedtest in the first half of 2018, according Telecompaper. The mobile operator averaged 21.6 Mbps in the Open Signal 4G tests in Q2, up 2 Mbps from six months earlier, and reached a score of 27.86 over the first half on Speedtest. Verizon came second in the tests, with average speeds of respectively 20.6 Mbps and 26.02. AT&T was third with an average 15.1 Mbps on Open Signal and 22.17 on Speedtest. Sprint reached respectively 14.5 Mbps and 20.38. 
The Open Signal figures cover only download speeds and are based on user measurements over an app. Speedtest combines both download (90%) and upload (10%) speeds recorded on its website to come to its scores. In 4G upload speeds, T-Mobile also came first on Open Signal's tests, with an average 7.5 Mbps, while Sprint was last at 2.5 Mbps. 
T-Mobile also took the top scores for 3G latency and 4G availability at Open Signal. AT&T won 4G latency, and Verizon tied for 4G availability, with each providing a 4G signal an average 93.7 percent of the time. Ookla attributed the strong performance by T-Mobile to its use of nearly all its mid-band spectrum for LTE, as well as LAA to boost capacity in congested areas.