We took to the road with Broadband Genie to test mobile broadband under real-world conditions over the length of the UK. We traveled from London to Edinburgh to discover which 3G and 4G networks are best for speed, best for reliability. (For the full results of our survey, see UK's best 3G network 2014: best 3G, best 4G, best mobile networks revealed.)

We tested 3G- and 4G mobile broadband on the four main networks with a selection of tasks designed to emulate actual usage and push performance to the limit.

The major mobile broadband providers who agreed to take part in our test were 3, EE, O2, Vodafone. EE incorporates Orange and T-Mobile, so we were testing all of the UK's nationally available mobile networks.

We asked each vendor to provide us with a 3G and a 4G dongle, and over the course of two days we took a train from London to Edinburgh and back, carrying out 39 tests along the way. Each network was tested by a dedicated individual, so that each test took place at exactly the same time, in exactly the same location. Teats included speed tests, video-streaming tests, downloads and uploads. For each test a maximum time was allowed. (See also: laptop vs smartphone vs tablet - what's the best tech to use on the move.)

UK's fastest 3G and 4G network 2014

Three is also the UK's fastest mobile network, on 4G and 3G. EE was once again the runner up, being the second fastest 3G and 4G network in the UK.

Three speed scores:

  • Average download speed: 6.19Mb
  • Average upload speed: 1.54Mb
  • Fastest speed test result: 19.53Mb

O2 isn't far behind EE. Last but not least of the UK's best 3G- and 4G networks is Vodafone. Its results were a little poor.

The average speed of all networks this year were a big improvement on 2013's average.

UK's best 3G and 4G network coverage 2014

We measure coverage and reliability based on how many of the download, upload and video-streaming tests that each network completed as we traveled the country for two days. Three came out on top again.

Tests completed:

  • Three: 90 percent
  • EE: 73 percent
  • O2: 23 percent
  • Vodafone: 23 percent

EE was once again our runner up, completing a decent total of the tests. We then have a big drop to O2 and Vodafone.

UK's best 3G network 2014

Of the four 3G networks on test Three demonstrated the best performance. EE was good but not quite as good, and the 3G O2 dongle gave a strong performance let down by reliability. Vodafone managed to complete just 10 percent of all the task and had meagre average speeds.

UK's best 4G network 2014

Guess what: Three was the best 4G network, too. EE was not able to match Three on speed or coverage, but still performed well. O2 4G did beat EE in average speeds, unfortunately with only a 23 percent test completion rate it appears O2’s network lacks the reach of EE. Vodafone 4G made up for the weak results of the 3G service with decent average- and peak speeds. Unfortunately it struggled to hold on to a signal.

UK's best mobile network of 2014

So we can confidently say that Three is the UK's best mobile network of 2014. Both on 3G and 4G Three completed more tests than did any other network. Three was the fastest network with excellent average and peak scores in our speed tests up and down the country.

A very good runner up to Three in the UK's best mobile network of 2014 category was EE. Read more at Broadband Genie's 2014 Road Trip site.