What is ADSL broadband and what’s the best alternative?

ADSL broadband is a type of internet connection that uses phone lines to connect you to the internet. Unlike the dial-up connections it replaced, which tied up the phone line and required you to "dial in" every time, ADSL is always on. This means you can use the internet and make phone calls at the same time without interruptions.  

ADSL is called "asymmetric" because the download speed (getting data from the internet to your device) is much faster than the upload speed (sending data from your device to the internet). This works well for most people, as activities like streaming videos or browsing websites require more downloading than uploading.  

But ADSL has some serious limitations. For one, your internet speed depends on how far you live from the telephone exchange (the building that connects local lines to the broader network). The farther you are, the weaker the signal becomes, which can lead to slower speeds.  

ADSL reuses old copper phone lines to deliver internet by splitting signals, prioritising downloads, and staying always connected. Your phone line is split into two parts using a small device called a splitter or microfilter, with one part handling regular phone calls, while the other part carries internet data.  

This split happens because phone calls use low-frequency sound waves (like talking), and the internet data uses high-frequency signals. By separating these frequencies, your phone and internet can work at the same time without interfering with each other. 

The ADSL modem then translates digital data from your computer into electrical signals. These signals travel over the copper telephone wires to your internet provider’s network, so you don’t need to "dial in" like old dial-up connections. Instead, it’s just on all the time.  

Download speeds for ADSL range from 5 to 24 mbps depending on your setup, while upload speeds are much slower, usually between 1 to 3 Mbps. These speeds are fine for everyday internet use but are nowhere near as fast as fibre or gigabit broadband packages.  

Internet providers often advertise ADSL as "up to 24 Mbps," but real-world speeds are often lower. If you’re in a busy area with lots of users, speeds might dip during peak times.  

Your actual speed can also be slower if you live far away from your nearest telephone exchange. The further you are from this, the more chance of the signal weakening and your internet speed slowing as it travels over old copper phone lines.  

Someone 1 mile from the exchange, for instance, might get 20 Mbps, while someone 3 miles away might only get 5 Mbps. Copper wires can also suffer from interferences from other devices or weather conditions can also affect your ADSL speed.  

ADSL and VDSL both use telephone lines, but VDSL is much faster. ADSL offers download speeds up to 24 Mbps and uploads around 1-3 Mbps, while VDSL can reach 100 Mbps downloads and 10-20 Mbps uploads. 

This difference in speed comes from how they use the phone line’s “space”: VDSL splits the line into more frequency bands, allowing more data to flow at once. But both still rely on copper wires, so your speeds will drop the farther you are from the network hub.  

ADSL is more widely available than VDSL, especially in rural areas, because it works over older phone lines. VDSL requires upgraded infrastructure (like fibre-optic cables part of the way to your home), so it’s mostly found in cities or suburbs. It’s still not as fast or as future-proof as full fibre broadband though, so you’re better off looking at fibre broadband for getting connected at home.

In 2025, the best alternative to ADSL is fibre broadband, which is widely available across the UK. Not only can you get superfast fibre broadband at a low-cost, but it’s much faster and reliable than ADSL since it ditches slow copper wires for fibre optic cables.  

Unlike ADSL, Fibre uses fibre-optic cables that send data as light signals, making it far faster and more reliable than ADSL with its copper lines. This means smoother streaming, faster downloads, and better performance for busy households with multiple devices. 

Not sure if fibre is available in your area? Use our helpful postcode checker to see what you can get. 

With our superfast fibre broadband, you can stream, game, and work seamlessly on multiple devices, all at once. Bundle lightning-fast fibre with TV channels, crystal-clear calls, and hassle-free setup.   

Check out our broadband deals to and use our helpful postcode checker to see what's available in your area.