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How fast is 4G? - 4G speeds and UK network performance

4G Speeds

You’d have to be living in a cave to not know 4G was faster than 3G, but just how much faster is it really? And what practical difference does the speed make? We've got the answers.

To understand just how fast 4G is, we need to put the technology into perspective against the older mobile network technologies, namely 3G and 3G HSPA+. To do so we'll look at the theoretical and real-world performance of 4G LTE, as well as looking 4G speeds on the UK's mobile networks.

Theoretical/Real World Speeds by network technology

When it comes to measuring mobile network speeds there are two situations which are of interest, theoretical and the real world.

Theoretical speeds are those which you can expect to obtain in a laboratory environment with perfect conditions, while real world speeds are those you can expect to get everyday using your phone on a real mobile network.

To benchmark network speeds, we are interested in download and upload speeds.

Download speeds are the rate at which mobile data is transferred from the internet to your phone or mobile device e.g. downloading a video. While upload speeds are the rate that mobile data is transferred from your phone or mobile device to the internet e.g. uploading a photo to Facebook.

Theoretical 4G Download Speeds

Real world 4G Download Speeds

3G is the slowest speed you’ll usually be browsing on. It has a typical real-world download speed of 3Mbps and a theoretical maximum download speed of 7.2Mbps. If you want to stream a video via 3G from YouTube for example you could be waiting up to ten seconds for it to load. While downloading a 500MB file can take around 22 minutes, with larger apps, movies and albums taking far longer still.

Basic 3G‘s upload speed is a lot slower than its download speed, with typical speeds of 0.4Mbps and a theoretical limit of 2Mbps. In practice 3G is generally fine for web browsing and social networks, you’ll just have to wait a few seconds for pages to load. It would take 25 seconds to upload a 10MB file or image.

3G HSPA+ is an enhanced version of 3G, which for example Three uses for its Ultrafast service. It offers typical download speeds of 6Mbps and a theoretical maximum of 42Mbps. You can expect streaming videos to load in around 5 seconds and medium sized apps to download in one minute plus, whilst the same 500MB file mentioned above would take 11 minutes to download.

3G HSPA+ provides upload speeds of around 3Mbps and the theoretical maximum is around 22Mbps. A 10MB file or image would take just over 8 seconds to download. Most of the time you’ll now be getting at least 3G HSPA+ speeds on UK networks.

4G (4G LTE) is the fastest speed that’s widely available in the UK right now. It offers typical download speeds of around 20Mbps and theoretical ones of 150Mbps. So for example you could download a medium sized app in under 15 seconds or load a YouTube video in under 2 seconds. The same 500MB file should be downloadable in under 4 minutes.

4G boosts upload speeds to 8Mbps on average and 50Mbps at the very top end. The same 10MB file or image would take just 1.25 seconds to download.

4G LTE-Advanced is a faster version of 4G with typical real-world download speeds of 42Mbps and theoretical limits of 300Mbps. EE has launched this service in London, Birmingham and Manchester under the name 4G+, while Vodafone has rolled it out to London, Birmingham and Manchester. With LTE-Advanced (also known as 4G+, LTE-A or 4.5G) videos will load without a discernible pause and a 500MB file will download in under 2 minutes. In fact, it’s even faster than many home broadband connections.

4G LTE-Advanced offers upload speeds of 30Mbps and can theoretically reach 150Mbps. In this case the same 10MB file or image would take just 0.33 seconds to download.


Download and upload speeds aren’t the only things that have been improved because 4G also has a better response time than 3G – due to lower “latency”. This means that a device connected to a 4G mobile network will get a quicker response to a request than the same device connected to a 3G mobile network.

The improved latency times, reduced from around 80 milliseconds (3G/3G HSPA+) to around 45 milliseconds (4G), may not seem that significant on paper. However, they can make a significant difference when playing online games and streaming live video.

UK Network 4G Speeds - Which UK network offers the fastest 4G?

There have been a number of studies conducted to compare 4G speeds on the UK's 4 major networks, but we've picked out two of the most important ones, namely OpenSignal in September 2017 and Speedtest.net Mobile Speedtest Data Q3-Q4 2017.

OpenSignal – Mobile Networks Update, September 2017


4G download speeds (Mbps)

4G latency (ms)













One of the most recent comprehensive studies into 4G speeds on UK networks was carried out by OpenSignal, using data gathered from 51,944 test devices and 829,136,423 measurements.

You can see EE is substantially ahead of rivals when it comes to average download speeds and almost the best for latency.

Speedtest – Mobile Speedtest Data, Q3-Q4 2017


Download/upload speeds (Mbps)









A recent test by Speedtest also shows EE on top – for both average download and upload speeds. Note that it doesn’t separate 4G from 3G, but given the speeds shown most samples were probably on a 4G network.


EE is still clearly the fastest 4G network with speeds up to 50 per cent faster than the other 3 networks. Vodafone and Three are now on a pretty level footing across the UK in terms of average 4G upload and download speeds, but O2 is notably slightly behind in tests.

Three is also the most improved network when you compare these results to how it used to be, but all four networks are heading in the right direction, with 4G speeds remaining stable or increasing.

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