Three had the smallest median 4G footprint.
EE offers the largest 4G footprint with the fastest speed in the UK, according to research from RootMetrics.
The research showed that EE had a median 4G footprint of 79.3 percent, far exceeding closest competitor Vodafone which offers 58.2 percent. O2 and Three followed with 52.7 percent and 24.8 percent respectively.
EE also offered 4G in all 16 markets surveyed, offering a 92.9 percent footprint in Belfast, while Three offered 4G in 14 markets. Vodafone and O2 both offered the service in 13 of the markets tested.
EE’s maximum download speed was 94.1 Mbps, measured in Belfast, while O2’s was 64.7 Mbps in London. Vodafone recorded 64.5 Mbps in Belfast and London and Three recorded 50 Mbps in Sheffield. EE also offered median speeds above 20 Mbps in 12 markets.
However, Three was the strongest performer when 4G was unavailable, offering 7.3 Mbps in Belfast. EE’s fastest was 4.9 Mbps, while Vodafone barely topped 3 Mbps and O2 never passed it.
"2014 was the first year in the UK when all the major networks were providing 4G services, and it appears each has had its success in deploying services across the country," said RootMetrics CEO and President Bill Moore.
"We have seen some startlingly fast speeds in pockets of the UK and overall median speeds are substantially higher than 3G. What is even more encouraging is the reliability of services once customers are on 4G. The growing footprint of each network means as more customers are able to access 4G, they will be able to consistently access all the benefits 4G brings."
The tests were conducted in the second half of 2014, examining the 16 most populous metropolitan areas in the UK.