London’s mobile networks have fallen to the bottom of the European capital league. Ookla’s third quarter 2026 tests gave the city the slowest median download speed of 18 capitals at 109.43 megabits per second, the slowest median upload at 11.40 megabits per second, and the highest latency under load. London ranked seventh in 2021, and its 5G median peaked at 200 megabits per second in the second quarter of that year; Paris has stayed above 225 megabits per second since mid 2021.
The driver is congestion. In central London, weekday performance slumps as commuters arrive, with median download speed falling to 80.07 megabits per second through the morning, 27 percent below weekend levels at the same hours, while capacity has not kept pace with traffic.
Ookla points to site economics and planning. UK operators own few antenna sites, and many sit on rooftops. Changes to the Electronic Communications Code in 2017 cut a London rooftop’s value to its owner from about 21,000 pounds a year to about 1,000 pounds, leaving landlords little reason to host antennas, and redevelopment notices keep an estimated 7 percent of rooftop sites out of action at any time. Applications for new street masts peaked in 2020 and have fallen by more than four fifths since 2022; about three quarters of applications filed since 2019 were refused, against one in five upgrades.
A draft City Hall plan, due for adoption in 2028, would require developers to keep mobile service running during construction and press boroughs to work with operators on conservation area sites. Other experts blame the Huawei rip and replace programme for diverting funds from capacity building.