Mobile data speeds in Newcastle are faster than London or anywhere else in the UK, according to testing research.

According to performance research company RootMetrics, 4G operator EE in Newcastle clocked average download speeds of 14.7mbps, and upload speeds of 9.7mbps. The latest 4G EE London speed figures were 13.6mbps (download) and 8.4mbps (upload).

In tests in Newcastle it took EE just 3.5 seconds to download 10 emails and under a second to load a typical web page.

At the same time, Three and O2 have also improved their speeds in Newcastle. Three's average mobile internet download speed has nearly tripled to 6.8mbps since the same tests were carried out in September 2012. This download speed is the fastest speed RootMetrics has recorded by Three in any UK city to date. O2's average download speed - 3.6mbps - was nearly twice as fast as the speed found in Newcastle in September 2012.

Three was the only other operator to show an average time to load a webpage at under a second, but when it comes to the average time to download 10 emails it was the slowest of all the operators at 6.6 seconds. Vodafone demonstrated the slowest average time for loading a "typical webpage" at 3.7 seconds.

On overall network reliability - how often each operator successfully connected to the network and once connected, how reliable each operator was at completing speed tests, successfully downloading emails, and loading webpages or apps - Three's network was most reliable with a score of 98.3 (out of 100). Vodafone was last with a score of 90.2.

In the past when it has found itself at the bottom of the list in Rootmetrics tests, Vodafone has disputed the reliability and methodology of the tests carried out by Rootmetrics. The testing company maintains they are valid.

In the tests, when EE's 4G service cannot be automatically connected to, the phones used for testing revert back to the EE 3G or 2G network. "RootMetrics uses off-the-shelf, unaltered devices, so they work the same way regular customers' devices do," said the testing firm. "Results are therefore based on the best connection an operator can offer at any given time," it said.