Last reviewed: June 2026 | Source: Ofcom and Openreach
TL;DR- ADSL broadband delivers internet over the copper telephone line into a home.
- Typical ADSL download speeds are around 10 to 24 megabits per second, often slower over longer lines.
- FTTC and FTTP use fibre for part or all of the connection and are much faster than ADSL.
- The traditional analogue phone network is being switched off, with the migration to digital landlines under way.
- Openreach is rolling out full fibre across the UK, replacing older copper-based services over time.
Key Facts
●Technology: Asymmetric Digital Subscriber Line over copper phone lines
●Typical ADSL download speed: Around 10 to 24 Mbps
●ADSL2+ maximum: Up to around 24 Mbps
●Faster alternatives: FTTC (fibre to the cabinet) and FTTP (full fibre)
●PSTN switch-off: Analogue phone network being retired to digital
●Network builder: Openreach full fibre rollout across the UK
ADSL was for years the standard way most UK homes connected to the internet, using the same copper lines as the telephone. As fibre has spread, ADSL has become the slowest mainstream option, and the wider retirement of the old copper phone network is changing the landscape further. This guide explains what ADSL is, the speeds it delivers, how it compares with fibre options, the switch-off of the analogue phone network and what to do if ADSL is the only service available.
What ADSL broadband is
ADSL stands for Asymmetric Digital Subscriber Line, a technology that delivers broadband over the existing copper telephone line into a property. It is asymmetric because download speeds are higher than upload speeds, reflecting how most people use the internet, with more data coming in than going out.
ADSL was the technology that brought always-on broadband to millions of UK homes, using the telephone wiring already in place rather than requiring new cables. A filter or splitter separates the broadband signal from the voice signal so the line can carry both at once.
Because it relies on the copper line all the way from the local exchange, ADSL performance depends heavily on the distance and quality of that line. This is the key limitation that newer fibre technologies were designed to overcome.
Typical ADSL speeds
Typical ADSL download speeds are in the region of 10 to 24 megabits per second, with the later ADSL2plus standard capable of up to around 24 Mbps under good conditions. Upload speeds are considerably lower, often around 1 Mbps, reflecting the asymmetric design.
Actual speeds vary widely because the signal weakens over the length of the copper line between the property and the exchange. Homes far from the exchange can experience speeds well below the maximum, sometimes only a few megabits per second, while those close by may approach the upper figures.
By modern standards these speeds are slow, particularly for households streaming high-definition video on multiple devices or working from home. This gap between ADSL and the demands of current internet use is the main reason customers move to fibre where it is available.
ADSL versus FTTC and FTTP
FTTC, or fibre to the cabinet, uses fibre from the exchange to the green street cabinet and then copper for the final stretch to the home, delivering much higher speeds than ADSL, commonly several tens of megabits per second. FTTP, or fibre to the premises, runs fibre all the way to the property and can deliver speeds far higher again, often hundreds of megabits per second or more.
The difference is dramatic: where ADSL might offer 10 to 24 Mbps, FTTC typically offers far more and FTTP can offer speeds an order of magnitude higher. Upload speeds also improve substantially with fibre, which matters for video calls and uploading large files.
Because of these differences, most customers who can get FTTC or FTTP gain a noticeable improvement over ADSL. The availability of these services depends on whether the local network has been upgraded, which is the focus of the Openreach rollout.
The PSTN switch-off
The traditional analogue telephone network, known as the Public Switched Telephone Network or PSTN, is being retired as the UK moves to digital landline services that work over broadband. This migration affects how home phone calls are carried and is being managed by the industry over a defined period.
For broadband, the switch-off is part of a wider move away from older copper-based services toward digital and fibre technologies. Customers on services that rely on the analogue network are being migrated to digital alternatives, and providers are contacting affected customers about the change.
The switch-off matters because it signals the gradual end of the technology underpinning ADSL and analogue phone lines. Households should be aware of communications from their provider about migrating to a digital service, particularly where devices such as alarms or telecare equipment rely on the old line.
The Openreach full fibre rollout
Openreach, which builds and maintains much of the UK's fixed network, is rolling out full fibre, or FTTP, across the country, replacing older copper-based connections over time. This programme is steadily expanding the number of premises that can access full fibre broadband.
As full fibre reaches an area, customers gain access to much faster and more reliable broadband than ADSL or even FTTC can provide. Over the long term, the rollout is part of the move away from the copper network that ADSL depends on.
Other network builders are also expanding fibre in many areas, increasing competition and choice. Customers can check availability through their provider or an address checker to see whether full fibre has reached their property, since rollout progress varies by location.
What to do if only ADSL is available
Some properties, particularly in rural areas, may still only have ADSL available, in which case the practical options are to make the best of the service or to look at alternatives. Checking availability regularly is worthwhile, because fibre rollout is ongoing and a faster service may become available over time.
Where fibre is not yet available, alternatives can include mobile broadband using 4G or 5G where coverage is good, or other technologies in some areas. The suitability of these depends on local signal and the household's usage, so it is worth checking coverage before relying on them.
For homes that struggle to get a usable connection, there are universal service provisions designed to ensure a minimum standard of broadband, and Ofcom provides information on the rights and options available. Households should check what schemes apply and keep monitoring fibre rollout in their area.
It can also be worth contacting the provider to confirm the actual line speed being delivered, because a poor ADSL connection is sometimes caused by a line fault rather than distance from the exchange. Where a line is not performing as expected, the provider can investigate, and in some cases improvements or a fault repair can restore the speed to the level the line should support before any decision about alternatives is needed.
Frequently Asked Questions
What is ADSL broadband?
ADSL, or Asymmetric Digital Subscriber Line, is a broadband technology that delivers internet over the existing copper telephone line into a home. It is asymmetric because download speeds are higher than upload speeds. ADSL brought always-on broadband to millions of UK homes using existing phone wiring, but because it relies on the copper line all the way to the exchange, its performance depends heavily on the distance and quality of that line.
How fast is ADSL broadband?
Typical ADSL download speeds are around 10 to 24 megabits per second, with the ADSL2plus standard capable of up to around 24 Mbps in good conditions, while upload speeds are much lower. Actual speeds vary widely because the signal weakens over the length of the copper line, so homes far from the exchange may get only a few megabits per second. By modern standards these speeds are slow for streaming and home working.
Should I upgrade from ADSL to fibre?
If FTTC or FTTP fibre is available at your address, it will generally deliver far faster and more reliable speeds than ADSL, with much better upload performance for video calls and uploading files. Whether to switch depends on availability, cost and your household's usage. You can check what is available through your provider or an address checker, as fibre rollout progress varies significantly by location.
What can I do if only ADSL is available in my area?
If only ADSL is available, check availability regularly because fibre rollout is ongoing and a faster service may arrive over time. Alternatives can include 4G or 5G mobile broadband where coverage is good, depending on your local signal and usage. For homes that cannot get a usable connection, universal service provisions exist to ensure a minimum standard, and Ofcom provides information on the rights and options available.
