5G vs 4G: What’s the difference and does it matter?

Before its launch, 5G was heralded as ushering in a new era of connectivity. The official switch-on in the UK happened in 2019 and, since then, the major mobile phone networks have continued to expand their coverage across the country.

According to data from Ofcom – the UK’s communication services regulator – 5G now covers 92% of UK premises, with occupants being able to access 5G outdoors. Of course, that’s slightly different to 92% of the total population or 92% of land coverage, since most premises are densely packed into urban areas.

But what is 5G? How does it differ from 4G? And, more importantly, what difference does it make to you, the user?

What is 5G?

When we talk about mobile phone networks, it was really 3G that laid the foundation for the ‘G’ naming we’re all now familiar with. Prior to the launch of 3G in 2003, mobile phone networks were more referred to as GPRS and EDGE. With that in mind, the naming makes sense: 5G is the fifth-generation network – the ‘G’ stands for ‘generation’.

Brian Potterill, policy director at Ofcom, told me: “5G is the latest generation of wireless technology, which can provide more capacity for people using mobile services. It can allow thousands of devices in a small area to be connected at the same time”.

That boost in connectivity allows for things like the seamless streaming of high-definition video and nearly instantaneous music downloads, as well as more immersive experiences like virtual reality.

What is 4G?

If 5G is the fifth-generation network then you’ve probably already worked out what 4G is – the fourth-generation equivalent. But 4G held a different name too, and was called LTE in some parts of the world. You’ll still see references to LTE on some phones (including VoLTE, or ‘voice over LTE’).

This 4G network launched in the UK in 2012, brought us into the period of ‘mobile broadband’, taking the mobile data experience that started with 3G and expanding it. The roll-out of 4G also brought a much wider range of apps and services, as the always-connected experience was great for things like delivery apps and Uber.

The 4G network is well established in the UK, which is why you’ll often find that you’re connected to 4G on most modern smartphones, even if you have a 5G-capable device. According to Ofcom data, 93% of the UK landmass has 4G coverage from at least one network, meaning that nearly everyone will have access.

How much faster is 5G than 4G?

The difference between 5G and 4G can be quite variable, depending on whether you’re talking about theory or practice.

In theory, 5G can be drastically faster than 4G – it has the technical capacity to offer 20 Gbits/sec (gigabits per second), compared to 4G’s upper limit of 100 Mbits/sec (megabits per second). That’s a huge margin, but it’s dependent on ideal conditions and close proximity to a 5G cell tower, both of which rarely happen.

In practice, you can expect your speed to vary depending on a range of factors. Chipmaker Qualcomm – which has had a huge hand in 5G infrastructure – told me that, “under real-world conditions, a user could download a cinematic length 8K movie around five times faster over 5G than with 4G LTE, but this all depends on strength of signal and other factors”.

On average, the speed advantage of using 5G, compared to 4G, should hover somewhere between twice as fast and ten times as fast, but your actual real-world experience can be very different. Running a quick speedtest at my desk, the fastest download speed I got from 5G was 90Mbps, while 4G was 45Mbps; however, the speeds were basically the same for uploading, illustrating how theory and practice can differ.

Does 5G use more battery?

When 5G phones first arrived on the market and the relevant networks were being built, it didn’t take long for people to notice something was up and there has been plenty of talk about 5G battery drain. Both Apple and Samsung refer to greater battery usage on their support pages.

But there are multiple issues at play here, and Qualcomm told us it’s not as simple as it might sound. When asked if 5G used more battery than 4G, a Qualcomm spokesperson said: “In a word, no. 5G is more spectrally efficient than 4G so it allows quicker downloads and your phone spends less time downloading. Of course, if you then start watching a movie on your phone then you may be using more of your phone’s battery life”.

The other factor is that 5G is only used for data, so your phone needs to maintain a connection to other networks for voice. Often, that will mean using both 4G and 5G at the same time. Rest assured this won’t always be the case, as voice will be supported over 5G in the future.

Called VoNR, or Voice over New Radio, this 5G technology will be used to replace voice services on older mobile networks and it should reduce power demand in mobile devices. There’s no confirmed timeline for the switch to VoNR, but in September 2023, EE confirmed that it had made the UK’s first 5G voice call.

If you’re concerned about battery life while on a trip or a day out, turning 5G off could get you a small uplift. However, exactly how much battery you’ll save will vary massively day-to-day and phone-by-phone, depending on how much you use your phone and what you use it for. If you’re a heavy 5G user and your current battery isn’t up to it, then investing in a phone with the best battery life will stop you getting caught short when out and about.

What does 5G do that 4G can’t?

If battery life is an area that networks, tech companies and phone manufacturers can’t boast about 5G, what makes it better than 4G?

There are plenty of areas where the faster network is an advantage. When it comes to latency, in particular, 5G is a big improvement over 4G. Latency is the delay in communication across a network, and this is one area where 5G is much faster, making it a major upgrade for gamers playing the likes of Call of Duty: Mobile.

Brian Poterill, from Ofcom, backs this up: “The biggest difference compared to 4G is the speed. Gaming, streaming or browsing the internet on a mobile phone connected to 5G is much quicker.”

5G also has a far higher ceiling when it comes to network saturation – it can handle many more device connections before it reaches capacity. This should mean that, as 5G becomes more and more established, we should have fewer situations – like when you’re in a big crowd at a sports game or an arena concert – where you might experience network dropouts. It’s also one of the reasons that mobile phone brands like to sponsor mass participation events, like Glastonbury and Wembley Stadium.

“Increasingly, networks rely upon 5G to deliver capacity. So, even if consumers don’t want the very high speed they might get with 5G, if they can only use 4G they may experience network congestion more often”, Potterill says.

Finally, even though you can still download a song, video or movie over 4G, the simple reality is that because 5G is so much faster in good conditions, downloads are often incomparably faster, making them far more feasible.

Do I need a 5G phone?

If you want access to 5G speeds then yes, you need a 5G phone. Since 5G technology requires different hardware, you need a phone that’s 5G-ready in order to access the network.

The fact is that the majority of new smartphones in the last few years have been 5G-capable as standard. Some budget phones might still be 4G-only, but that’s become increasingly rare in 2024. Brian Potterill tells me: “Most mobiles do now support 5G and there’s often not a big price difference”.

There’s good news too as, if you pick up a phone that works with 5G, you’ll definitely be able to access 4G . Similarly, if you’re curious whether a 5G SIM card will work in a 4G phone, the answer is also yes. The vast majority of phone contracts now either include 5G speed as standard, or they will let you know if you’re limited to only 4G networks.

If you do have 5G included in your contract, you’ll still be able to use 4G (and indeed 3G) when 5G isn’t available.