London’s mobile networks fall to bottom of Europe’s capital league

London's mobile network performance has slipped behind other European capitals as operators struggle to add capacity fast enough to meet demand.

The city ranked seventh out of 18 in the continent for median download speed in 2021, but traffic has since expanded faster than available capacity.

Other metropolises have improved; London now has the slowest speeds and the highest latency under load, according to mobile network testing firm Ookla .

The research points to obstacles mobile operators face in adding extra capacity: applications for new street masts in London have fallen since 2022, and about three quarters of those filed since 2019 were refused.

The Big Smoke was among the first European capitals to get 5G coverage, yet when Ookla's Q3 2026 tests found the city now has the slowest median download speed (109.43 Mbps), the slowest median upload speed (11.40 Mbps) and the highest latency under load - a measure of how the network copes with heavy use.

Ookla's records show London’s 5G medina speed peaked at 200 Mbps in Q2 2021, fell as low as 102 Mbps in Q3 2023, then recovered slightly.

Paris, by contrast, has stayed above 225 Mbps since mid-2021.

The cause is congestion.

In Central London, performance slumps on weekdays as commuters arrive: median download speed falls to 80.07 Mbps through the morning, 27 percent below weekend levels at the same hours.

Part of the problem is that UK mobile operators own few of their antenna sites, many of which sit on rooftops in built-up areas, says Ookla.

Under the Electronic Communications Code, and changes introduced in 2017, a London rooftop is worth about £1,000 ($1,333) a year to its owner, down from £21,000 ($28k).

That givers landlords little motivation to host antennas, and many prefer solar panels.

Operators can also receive notices to quit when a building is redeveloped, and it is estimated that this keeps about 7 percent of London’s rooftop sites out of action at any time.

Planning rules compound the problem as applications for new masts are more likely to be refused in boroughs with conservation areas, such as Westminster.