3 had the fastest median 5G download speed in the U.K., EE had the highest 5G Availability. Speedtest Intelligence revealed a decisive win for U.K. operator 3 during Q1-Q2 2021, with a median 5G download speed of 231.07 Mbps. Vodafone followed at 159.49 Mbps , O2 was next at 155.54 Mbps and EE last at 151.03 Mbps.