Three offers best UK mobile coverage, according to OpenSignal

The mobile network Three offers the best signal coverage in the UK, according to data from OpenSignal.

The organisation, which crowdsources information on mobile signal from Android and iOS users via an app, has produced an interactive heatmap showing mobile hotspots and notspots around the UK and the rest of the world.

Overall, Three offers 89% reliability across the UK on all mobile bands and is also the fastest of the four major mobile operators, with an average download speed of 3.79 Mbits/sec and average upload speed of 1 Mbits/sec.

At the other end of the scale are O2 and Vodafone. The latter was found to be the least reliable (83.43%) although it was the second fastest (2.5 Mbits/sec down, 0.56Mbits/sec up), while O2 offered better reliability (85%) but with much slower speeds (1.29 Mbits/sec down, 0.37 Mbits/sec up) and weaker overall signal.

Three is also the most reliable network for 4G, 2G and 3G individually, according to OpenSignal’s data, although EE offers greater overall coverage.

On 3G, EE is the least reliable (87.11%), while on 2G it’s Vodafone (83.2%). O2 is once again the slowest coming in at 1.98 Mbits/sec down and 0.36 Mbits/up on 3G and 1.7 Mbits/sec down and 0.29 Mbits/sec up on 2G.

The heatmap also lays bare the wide variation in mobile coverage levels around the UK. South East England, and London in particular, glows a fierce bright red, while much of Wales, the North of England, Scotland and Northern Ireland have no signal at all.

Coverage contradiction

One of the most intriguing things about OpenSignal’s data is it presents a very different picture of the mobile market to that produced by RootMetrics.

The company, which produces six-monthly assessments the state of the mobile market in the UK, is often used as a data source by Ofcom when preparing its own reports and has consistently found EE to be the joint most reliable network nationwide, as well as being the fastest. Vodafone, on the other hand, has consistently come out worst – a ranking the company has vociferously contested.

The most likely reason for this is the difference in methodology used by the two. RootMetrics travels to the 16 most populous Larger Urban Zones in the UK, including Belfast, Glasgow, Edinburgh, Cardiff and London, as well as a number of Built-Up Areas in England and Wales and Settlements Scotland and Northern Ireland to take measurements, whereas OpenSignal’s data is crowdsourced, potentially giving it a larger sample size more constant flow of data.