London may be the UK’s capital, but when it comes to 5G mobile performance, it continues to fall behind. A new analysis from Ookla, the network benchmarking company behind Speedtest.net, reveals that London ranks at the bottom of 5G performance tables among 11 major UK cities. Despite improvements in coverage and availability, the capital lags in key metrics like download speeds, consistency, and signal accessibility—a surprising result for a city with global infrastructure ambitions.
Ookla’s 2025 5G Performance Snapshot
Using crowdsourced data from Speedtest apps in Q1 2025, Ookla compared 5G performance across cities including London, Glasgow, Manchester, Leeds, and Birmingham. The study focused on median 5G download and upload speeds, network consistency, and coverage availability—all critical indicators of the mobile user experience.
Benchmarking mobile performance comes with challenges: user mobility, environmental obstructions, building materials, and the range of devices in use can all affect signal strength and speed. Despite these variables, the volume of data collected allows for meaningful city-level comparisons. The result: London remains one of the worst-performing cities for 5G, outpaced even by smaller urban centres like Sheffield and Cardiff.
London Ranks Lowest for 5G Download Speeds
London’s median 5G download speed was just 115.08 Mbps—the second-lowest among all cities in the report. In contrast, Glasgow topped the list with 184.99 Mbps, while Birmingham and Liverpool both delivered over 140 Mbps.
In addition to slower speeds, London also performed poorly in network consistency—a measure of how often users enjoy stable, usable speeds across typical mobile activities like browsing, streaming, and calling. For a capital city with heavy demand for connectivity, this result highlights an ongoing issue: 5G in London is available more often, but doesn’t deliver consistently high performance.
Why London’s 5G Performance is Falling Behind
Several interlinked factors continue to hamper London’s 5G rollout and reliability:
- Rooftop Access Delays: In dense urban areas like London, mobile operators rely heavily on rooftop sites to install 5G antennas. However, securing rooftop leases remains complex and slow due to property ownership disputes and long approval times.
- Building Design Barriers: Modern buildings often use materials that insulate heat and block radio signals—making indoor coverage harder to deliver. High-rise buildings with metal cladding, reinforced concrete, and energy-efficient windows can severely restrict signal penetration.
- Legal and Regulatory Obstacles: Reforms to the Electronic Communications Code in 2017 were meant to simplify site access. However, in practice, these changes have triggered legal disputes between property owners and telecom operators—slowing the deployment of new masts, especially in city centres.
- Spectrum Limitations: London’s networks rely heavily on the 3.5 GHz frequency band, which provides high capacity but struggles with indoor penetration and wide-area coverage. Without sufficient small cell deployment, this spectrum’s performance in London remains sub-optimal.
Infrastructure Improvements Are Closing Some Gaps
Despite lagging performance, there are signs of improvement. Londoners are spending less time in mobile “not-spots”—areas where no signal is available. In Q1 2023, around 3.7% of users were frequently without a signal. By Q1 2025, that figure had dropped to 0.7%.
This improvement is largely credited to investment in small cell infrastructure and efforts to expand mobile coverage across the London Underground and other key transit routes. Operator investment is helping to plug some of the more persistent coverage gaps, particularly in high-density areas and indoor locations.
5G Trends Across the UK
Ookla’s data shows that the issue isn’t unique to London. Across major UK cities, median 5G download speeds dropped by over 7% between Q1 2024 and Q1 2025. This decline is believed to be linked to network congestion, as operators retire older 3G infrastructure and shift more traffic onto 5G networks.
Interestingly, some cities saw a rise in 2G usage, particularly Birmingham and Manchester, as devices reverted to fallback networks during periods of congestion. This suggests that despite wider 5G availability, network performance under real-world load is still under strain—especially in heavily populated areas.
How Cities Rank – 5G Median Download Speeds in Q1 2025
| Rank | City | Median 5G Download Speed |
|---|---|---|
| 1 | Glasgow | 184.99 Mbps |
| 2 | Birmingham | 145.09 Mbps |
| 3 | Liverpool | 142.61 Mbps |
| 4 | Manchester | 142.24 Mbps |
| 5 | Leeds | 134.23 Mbps |
| 6 | Bristol | 130.42 Mbps |
| 7 | Cardiff | 123.19 Mbps |
| 8 | Edinburgh | 123.05 Mbps |
| 9 | Sheffield | 120.98 Mbps |
| 10 | London | 115.08 Mbps |
| 11 | Belfast | 114.38 Mbps |
These rankings show that London’s 5G download speeds are not only lower than average—they’re at the very bottom of the national performance scale, with only Belfast performing marginally worse.
5G Availability Improves, But Performance Lags
Interestingly, London leads all UK cities in 5G availability—with its coverage 13 percentage points higher than the national average. However, this lead has narrowed. In Q1 2024, Leeds had a 21-point advantage, suggesting that smaller towns and rural areas are catching up as operators expand their networks beyond the main cities.
This shift shows that while availability is no longer a major issue, performance and reliability are now the limiting factors in the user experience. A large number of cell sites means little if those sites can’t deliver consistent speeds or handle network congestion effectively.
Can London Close the 5G Gap?
London’s 5G challenges reflect the complexity of rolling out high-performance mobile networks in dense, heavily built environments. Coverage on paper doesn’t guarantee quality in practice. Factors like spectrum planning, site accessibility, and building density must all be addressed together.
Progress is being made—particularly in reducing signal not-spots and expanding coverage across transport networks—but the capital still lags behind cities with fewer physical and regulatory hurdles.
For London to catch up, it needs continued investment in small cells, greater rooftop access, and updated planning frameworks that support telecom infrastructure as a critical part of the city’s digital future. Without that, even the most connected city risks falling further behind.