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Mobile network benchmarking firm RootMetrics (Ookla) has today published their H2 2025 study of UK mobile networks (calls, texts etc.) and mobile broadband (4G, 5G) speeds. The results once again name EE as the best mobile operator after they scooped up the highest scores and fastest data speeds across most categories, while O2 languished at the bottom but has improved.
The study itself is based on the results of over 619,000 tests (some 786 indoor locations were tested and 22,800 miles driven on roads), conducted by a team of testers using off-the-shelf Smartphones between July and December 2025 (drive and walk tests), to measure the real-world performance of mobile operators in the United Kingdom. However, this study is focused on the results from 16 of the UK’s largest metropolitan markets, which isn’t much good at reflecting the impact of slower connectivity in rural areas.
The results shown below are typically split into several categories (network reliability, speed, data, call and text quality etc.) and each is assigned a score out of 100 (higher numbers = better). In terms of the UK-wide results, EE came top in every single category, with Three UK supplanting Vodafone as the runner-up (ironic perhaps, given their merger). By comparison, O2 echoed their results in other studies by coming bottom of almost everything.
In terms of the overall results, all but one mobile operator managed to improve their scores over the previous biannual study, with the biggest improvement being recorded by O2. By comparison, Vodafone was the only operator to see a fall in their score, although it wasn’t a huge fall. Otherwise, EE delivered the fastest median mobile broadband download speed of 114.1Mbps (up from 110.8Mbps), followed by Three UK on 53.8Mbps (up from 45.7Mbps), Vodafone on 47.7Mbps (down from 48.4Mbps) and O2 on 44.1Mbps (up sharply from 36.2Mbps).
Overall Scores for H2 2025 (vs H1 2025)
1. EE – 94.1 (93.2)
2. Three UK – 85.2 (84.2)
3. Vodafone – 84.2 (85.8)
4. O2 – 82.7 (80.1)
The below results summary also includes a performance split between England, Wales, Scotland and Northern Ireland.
The study also provided some results when looking at 5G-only mobile connections, which saw EE deliver the fastest median average download speeds of 236.7Mbps, followed by Three UK on 189.3Mbps, then Vodafone on 144.3Mbps and finally O2 on 111Mbps.
Mobile operators also continued to expand 5G availability for users across the UK. At the UK-wide level, both EE and O2 recorded a little over 75% 5G availability in 2H 2025, while Three UK followed at 66.1% and Vodafone trailed at 57.0%.
Looking back one year for greater context, UK-wide 5G availability among the operators ranged from 48.3% to 66.8% in 2H 2024, compared with 57% to 76.1% in 2H 2025, highlighting the continued expansion of 5G across the country.
However, Ookla’s RootMetrics report only provides bits and pieces of selected information, while we would have preferred to see a bit more detail (e.g. upload performance and latency) and a reflection of performance in rural areas too. But that is often the caveat with this type of scientific, albeit very manual, testing – there’s simply not enough data to give a complete picture of the UK.
One final point to make is that the results for Vodafone and Three UK are likely to go through some big changes over the coming year(s) as the two continue their post-merger network integration.