I signed up for fibre broadband a couple of years ago but am now wondering whether it is worth the cost. The only devices I use in my home are a six-year-old Toshiba Satellite L870 laptop and a Samsung tablet. I use them for email, web browsing and watching BBC iPlayer, but not much else. The laptop runs Windows 10 and works well enough so I don’t have any immediate plans to replace it.

If I revert to ordinary broadband, will I notice a reduction in performance in either device? Angela

You should notice a difference, because your “fibre” connection is probably about five times faster than you will get from ADSL2. However, for your purposes, the difference may not matter.

A few things drive the need for fast broadband. Today, the main one is usually a desire to stream movies from Netflix and similar services in good quality without lots of annoying pauses for buffering. It’s almost essential if you want to watch 4K or ultra high definition (UHD) video instead of HD (720p) or Full HD (1080p).

Families also need faster broadband when they are competing for bandwidth. It’s quite common to have people streaming different movies or TV programmes, watching YouTube videos and playing games at the same time. Gamers usually prefer fibre-style connections because they are more responsive: there’s less latency or lagging. People who still download large files will obviously prefer high-speed connections, too.

People who work from home definitely benefit from having responsive, fibre-style broadband. Aside from the advantages of much faster upload speeds – handy when you are sending files back to the office – the connections are more consistent and more reliable than ADSL. It’s very frustrating if your broadband connection drops just when you absolutely need it to work.

When I had ADSL at home, I always had a backup connection in the form of a laptop with a MiFi cellular dongle. After I upgraded to BT Infinity, I stopped bothering.

From your email, you don’t seem to fit into any of the needy categories. Even 5Mbps ADSL can handle email, web browsing and BBC iPlayer, though web pages won’t download as quickly.

And you won’t be alone. According to Ofcom, the UK’s communications regulator, about 95% of UK homes and offices could have superfast broadband if they wanted it. When Ofcom last surveyed the market in November 2018, only 66% of homes had taken the option. No doubt the number is higher today, but more than a quarter of British homes could still be using ADSL.

However, Ofcom’s 2018 Home Broadband Report (PDF) noted that average home download speeds had increased by 18% over the previous year to 54.2Mbps, with 16% of homes now getting 300Mbps from BT and 365Mbps from Virgin Media. Online services will inevitably cater for the growing majority. Users getting 10Mbps or less risk becoming second-class citizens.

Copper switch-off

Clearly, ADSL is not the future. You can downgrade your internet connection today, but the change will be temporary. Sooner or later, the analogue phone network will be switched off, much as the old analogue TV signal was switched off in 2012. You will then have to go back to a fibre-based service, on a date that will probably depend on exactly where you live.

Some countries are well ahead of us. For example, Estonia has already closed most if not all of its copper exchanges, and many Australian users have been given 18 months to switch to the country’s national broadband network (NBN). In the UK, telecoms companies have been discussing a 2027 switch-off date. The £30bn plan will need government support, but fibre will become as important economically as canals, railways and motorways were in their day.

Speed matters

One of the problems with delivering broadband over copper cables is that internet service providers (ISPs) cannot guarantee any particular speed. It depends on too many variables, including the distance from the telephone exchange, the quality of the wiring, the number of joints in the wiring, the faceplate in the home, the quality of the router, and the time of day. Broadband is a finite resource, so services are slower during peak times.

Previously, ISPs quoted the speeds that the various technologies could provide, whether that was ADSL, ADSL2+, FTTC, cable, wireless or whatever. This created frustration because only around 10% of customers actually got those speeds.

Last year, the Advertising Standards Authority introduced new rules that said speed claims “should be based on the download speed available to at least 50% of customers at peak time (8pm-10pm) and described in ads as ‘average’”. As a result, ISPs stopped quoting 14-17Mbps for ADSL2+ and started quoting 10-11Mbps. That is a fair reflection of actual speeds, but of course, millions of people will get below-average speeds. You could end up being one of them.

Choose a supplier

You can increase your chances of getting a reasonable speed by becoming an informed buyer. Start by checking your local telephone exchange with SamKnows’s UK Broadband Availability Checker. Type in your postcode or phone number and SamKnows will tell you which companies offer broadband in your area and how they deliver it.

In some areas, most ISPs are actually delivering exactly the same broadband because they are all using BT Wholesale services supplied by BT’s Openreach. They are all likely to run at roughly the same speed. You might get something better by switching to an ISP that has installed its own equipment via the local loop unbundling (LLU) scheme. In my local exchange, that includes Vodafone, TalkTalk and Zen. Their services might be faster or slower than BT Wholesale’s, but there’s more of a chance they will be different.

Note that joining or leaving LLU services is not always as easy as it is supposed to be, and involves an engineer changing connections in the exchange. Make sure you are not being charged for a new line. Also, you may have to pay a reconnection fee if and when you take the “return to donor” option and go back to BT.

Ideally, choose an ISP that subscribes to Ofcom’s voluntary code of conduct. This includes BT, EE, Plusnet, Sky, TalkTalk and Virgin Media. These ISP should give you an estimated speed in advance, based on testing your line. If they can’t deliver the minimum guaranteed speed within 30 days, you can quit the contract without being penalised.

Otherwise, Ofcom has some consumer advice and a useful checklist of things you need to establish before taking out a new broadband contract.

Talk to your ISP

Today, few UK users have their broadband delivered by fibre to their premises (FTTP). If you had speeds of 330Mbps to 1Gbps, you would know about it. Instead, most of us have FTTC, which is fibre delivered to the local street cabinet. When it leaves the cabinet, this “fibre broadband” is delivered over old copper wires using fast but short-range VDSL2, which used to require a separate modem but is now built into the router. This is how BT Infinity works.

As growing numbers of users have switched from ADSL to FTTC, this has become the most competitive part of the market, and it’s where you’ll find the best deals. Special offers mean you can sometimes get superfast FTTC services cheaper than slow ADSL services, so you may not be able to save as much as you think.

After researching the alternatives but before switching, talk to your ISP’s customer retention unit. Make a good case and they may be willing to match or even beat the competition, though this will usually involve signing up for a new 18-month contract.

When negotiating a new deal, you don’t have to limit it to broadband. Major ISPs offer lots of services including broadband, voice calls, mobile phone networks and television services. You may be able to save more money on a bundle than you would by downgrading to ADSL.

Have you got a question? Email it to Ask.Jack@theguardian.com