The H1 2025 Top Fastest UK Mobile and Home Broadband ISPs

ISPreview has today published our latest biannual study of how the United Kingdom’s broadband download and upload speeds have changed across the fastest nationally available fixed line ISPs, mobile network operators and Starlink (satellite) services since the end of 2024. But this time we’ve made some changes to the structure of our top lists.

As usual, the results in this report stem from consumer web-based speed testing and are thus inevitably impacted by a number of factors, such as the rising coverage of faster networks (e.g. full fibre and 5G) and the level of take-up by customers. As a result it helps to understand any key changes in network deployments over the same sort of period, which is shown below using Ofcom’s Spring 2025 Connected Nations data.

In terms of fixed line broadband lines, the primary coverage improvements have continued to come from Fibre-to-the-Premises (FTTP) networks (Summary of UK Full Fibre Builds). This is despite ongoing market pressures (i.e. rising build costs, high interest rates, fierce competition etc.) continuing to result in many alternative operators (altnets) suffering job losses and a slowdown in their deployment plans.

Full fibre networks are now also the sole driving force behind the rise in gigabit-capable coverage, which continues to be predominantly fuelled by commercial roll-outs in urban areas. Speaking of which, gigabit coverage passed the Government’s first target (85%) under their £5bn Project Gigabit programme earlier this year (this focuses on the final c.10-20% of rural premises) and is now aiming to hit c.99% coverage by 2032 (delayed from the original 2030 target – here).

Finally, in terms of mobile networks, there have been further improvements in 4G and 5G (mobile broadband) coverage. For example, the industry-led £1bn Shared Rural Network (SRN) project has made a little progress on boosting geographic 4G coverage and still aims to cover 95% of the UK – from at least one operator (84% from all operators combined) – by the end of 2025.

Fastest Major Fixed Broadband ISPs (H1 2025 vs H2 2024)

The data in this report has been gathered from Thinkbroadband’s independent speedtest database (inc. ISPreview’s Broadband Speedtest). The table below only includes the largest and most established independent ISPs with strong national availability, but there is a separate table for smaller providers directly below – these are difficult to include because such providers don’t produce much test data (fewer users).

Naturally, there are caveats to consider with speedtest based studies like this, not least because the results tend to be more reflective of take-up than network availability. For example, some ISPs may have a much larger proportion of customers on slower copper-based (ADSL or FTTC) lines, which can weigh against anybody on faster FTTP packages with the same provider (i.e. pulling average speeds down). The opposite can also be true.

However, the big change this time is that we’ve stopped doing a dedicated table for altnets, which is partly because some operators are wholesale-only (i.e. they lack a dedicated ISP for judging performance) and many other ISPs are now working with more than one underlying network operator. This has made doing an altnets-only table quite tedious and we’ve instead produced a second table that only includes the top 20 smaller ISPs (these do not require national availability and exclude those listed in the top 8 below).

Average Download Speeds – Top 8

Average Upload Speeds – Top 8

Overall, the average download speed of the top national providers was 90.12Mbps (up from 76.56Mbps) and the average upload speed hit 21.61Mbps (up from 15.88Mbps). The picture this time around is one of very mixed changes, with Zen Internet and EE showing big gains in download performance since the end of 2024, while for upload speeds the biggest gains came from Zen Internet, EE and Plusnet.

Now flick over to page 2 to continue this summary and see how the fastest satellite (starlink), mobile operators and smaller ISPs all performed.