The most important tech of the 21st century – according to Which? experts

From the millennium to now, tech has bound itself to every aspect of our lives, like ivy on a garden fence. It’s essential, transformative, problematic and there’s no going back.

With the help of tech experts across Which?, we’ve narrowed down the dizzying array of 21st-century technology to 15 innovations we feel have truly defined the past few decades. For better or worse, these devices, programs and inventions have changed the way we live forever.

Keep scrolling to find out which tech made our list and why, plus listen to our podcast for extra insight from our experts. You can also use our interactive tool to choose your own order.

Listen: Which? experts have their say

Join our tech experts for a chart show-style countdown as we reveal our definitive list.

1. Smartphones

They had to be number one. If you're not looking at it right now, you probably have yours with you; in your pocket, on the chair arm or a table. Even if it’s out of sight, you know where it is, and you’re statistically no more than 12 minutes away from checking it (whether you heard it chime or not).

It’s an extension of ourselves that has reshaped our habits and way of life to the point of addiction for some. Reaching for it is a reflex, where any downtime is phone time – it’s how phrases like ‘doomscrolling’ were born.

The reason isn’t just the smartphone. Apps are the glue that binds us to the screen, and however problematic our relationship with our phones might be, a life without them would be very difficult.

They are too useful and often essential for interacting with vital services, from banking to ordering prescriptions. Whether these are the easiest ways of using these services really depends on the quality of the app, but having such far-reaching control over so many aspects of life on a pocket computer that weighs less than a can of Coke would be difficult to imagine 20 years ago.

Their ubiquity wasn’t always a given, but the intuitive design and Apple’s marketing wizardry catapulted early smartphones to success, and the mobile world never looked back. The iOS and Android operating systems are honed to the point where even babies can use them instinctively.

It’s hard to make a case for any piece of tech changing the way we live and interact with the world more than the smartphone. It incorporates, utilises and enables many of the other things featured in this list and has changed our lives in more ways than we can count.

If you’re struggling with a sluggish mobile, it might be time for an upgrade – our guide to the best smartphones will help you choose wisely.

2. Broadband

Much of the advances we enjoy at home, on the go and at work are reliant on one thing: faster internet. We reached the point where dial-up just couldn’t cut it, and broadband was the only way to get the speed needed to support the modern world.

Dial-up’s maximum speed was just 56kbps – less than half a percent of the bandwidth needed to make an HD video call. 4K streaming requires up to 25Mbps per second (there are 1,000 kilobytes in a megabyte). Perhaps most striking is that one modern webpage, at around 2.5Mbps, would take the very quickest dial-up 44 seconds to load.

Now we can pay for speeds of up to 1Gbps, which is 17,857 times faster than dial-up, while the UK average is still a respectable 1,232 times faster. It’s easy to lose sight of these increases because the technology rises to meet them. Webpages are more demanding, content is at a higher resolution and more devices in the home are connected.

But the fact that it’s possible to run speakers, TVs, phones, games consoles, plugs, bulbs, tablets, laptops, thermostats, security cameras, doorbells and practically anything that can plug to your internet and not see sparks coming from your modem is testament to how much broadband’s accomplishments fly under the radar.

Best broadband deals – we’ve hand-picked the best value broadband-only, broadband and phone, and broadband and TV deals.

3. The App Store

We have Apple to thank for the fact that smartphone displays don’t all look like File Explorer on a Windows PC. And now, rows of brightly coloured tiles are how we interact with the world. Communication, banking, calendar, shopping, travel, events – if you can think of it, there’s an app for it.

The Apple App Store and Google Play Store that followed transformed phones from useful tools for calls and texts into Swiss Army knives with more than a million attachments. These enormous catalogues of apps and the talented developers who make them are why our phones are inseparable from modern life.

Discover the free smartphone apps Which? experts can't live without.

4. Google Maps

Anyone over a certain age will have a Pavlovian response to the Great Britain A-Z. You may find yourself short of breath, a vein on your forehead pulsing as you remember peering at tiny maps trying to figure out what street you’re on. Or you’re in the tiny minority who got a Duke of Edinburgh award for orienteering.

This is no criticism of the A-Z. It’s helped millions of people to find their way, but it’s a relic, and Google Maps is the reason why. Google’s extraordinary wealth and reach have allowed it to map just about everywhere on Earth, and anyone with the app can see where they are for free.

Map reading went from a skill to an afterthought, as advances to smartphones meant Google Maps could even tell which way you were facing. Walking, driving and even taking public transport were all incorporated, so you could see what trains or buses you’d need to get from A to B.

Google Maps has all but eradicated one of the most challenging, anxiety-inducing aspects of daily life, and absolutely deserves its spot in the pantheon of revolutionary 21st-century technology.

See Google Maps and Apple Maps features you need to try – whether you're planning a journey to see family or aiming to dodge traffic jams, our experts reveal how to get more from your map app.

5. Spotify

Few things can claim to have saved an industry while also being accused of destroying it, but few things have the significance of Spotify. At the turn of the century, illegal downloads were crushing music sales as people stopped buying CDs. It wasn’t until the launch of streaming services led by Spotify, that revenue started to recover.

Spotify capitalised on all the changes ushered in by illegal downloads, such as ease of discovery, playlists, offline listening and easier storage, and wrapped them up in a legal bow that meant studios could make money and people didn’t lose the convenience they were used to.

Its enormous popularity meant that few artists could afford to keep their music off the platform, and it wasn’t long before subscribers could access just about every recording ever made. It’s hard to imagine a time when you couldn’t type an artist’s name into an app and see their entire discography.

Spotify’s popularity brought power, and it’s easy to see how it exerts control over the music industry. There are several factors affecting artist royalties, and the exact amounts they receive isn’t made public, but meagre payouts are often cited for musician boycotts. Many artists are between a rock and a hard place. Only those with huge followings can really afford to remove themselves from the biggest music streaming service in the world.

For better or worse, Spotify changed how we listen, discover and engage with music. The ease and convenience is undeniable, but the need to be picked up in Spotify’s tailored playlists has led to a perceived homogenisation of music, which the advent of AI recordings will only worsen.

Our guide to the best streaming services will help you choose the right one.

6. Apple iPhone

In 2007, Apple made its competitors look like dinosaurs. This was when phones had number keys and navigation buttons, they flipped, they slid, they twisted – and were doomed. Existing ‘touchscreen’ phones weren’t really touchscreen at all; they came with a stylus and had interfaces that felt more like a miniature desktop than something made for mobile.

Apple upended the market then dominated it, and every brand had to follow. Those that didn’t, died. The iPhone’s supremacy was and is so great that former mobile juggernauts such as Blackberry, HTC, LG and Nokia were swallowed.

We’ll talk more about smartphones later, but the iPhone deserves its own spot on this list. It defined a market and still sits at the top of the heap, setting the tone and the agenda for the device we all have in our pockets.

Explore the best iPhone deals – our experts have rounded up top discounts on the iPhone 17, iPhone 16 and other models to help you find the best prices.

7. Apple iPod

The most popular tech of recent years has removed the obstacles that made it harder to enjoy the things we love, and when the iPod arrived in 2001, it freed entire music collections. It wasn’t the first MP3 player; that came in 1998, but the iPod soon got all the attention. Apple’s famously impressive marketing, iconic ‘1,000 songs in your pocket’ line and flair for design made the iPod one of the most sought-after products.

1,000 songs’ or 80 albums’ worth of music – far more than you could listen to in an entire day – on a box smaller than a passport was a tantalising promise and a remarkable achievement. It brought music out of the home and unlocked a physical media. This hadn’t happened before – it launched at a time with no Kindle, no smartphones with Netflix – but it was a sign of things to come.

Love your music? Do it justice with a pair of the best headphones.

8. Mobile internet

Mobile internet is a map in unfamiliar surroundings, a taxi in the rain, a recipe in the supermarket, a translation when abroad, a how-to video next to a broken down car. It’s entertainment, information and everything else on the go.

So many entries on this list owe 3G, 4G and 5G a debt of gratitude – mobile internet is the great enabler and easily one of the most life-changing developments in recent memory.

To uncover the best and worst UK mobile networks, we asked more than 4,000 members of the public to tell us about the networks they love – and the ones they hate.

9. Social media

Almost half the global population actively uses Facebook, owned by parent company Meta. Three billion people uploading photos, joining clubs, selling unwanted items and organising gatherings. In its purest form, it connects people and offers a platform to share thoughts, jokes and art. At its worst, it’s a tool used to spread dangerous disinformation, test scams, prey on the vulnerable and spread vitriol under the protection of anonymity and free speech. Facebook is wonderful and terrible – as is all social media.

While Facebook morphed from catching up with friends to a source of news, Twitter was always designed to be a hotbed of discourse on current affairs in a bite-sized format. When Elon Musk took over, he said Twitter (renamed X) was 'the digital town square where matters vital to humanity are debated'. His tenure has seen a spike in hate speech on X, with problematic voices seemingly welcome in the square.

Social media sits at the heart of our always-online culture. It’s intrinsically linked to so many important aspects of modern life, it’s no wonder so many people use it every day and will continue to do so.

Lock up the data you share online – learn how to secure your social media and email accounts.

10. NFC

Near Field Communication might be the most unassuming thing on this list – an invisible connection that allows you to pay on a card reader with your phone, watch or card without a Pin. It’s the ubiquity that makes it important.

It was adopted without much fanfare, helped by a reluctance to touch keypads and cash during Covid-19. Initial concerns around theft lost out to convenience, and now it’s the norm. We tap and we go.

11. AI

This will be a bigger fixture of the next 25 years, but even in its infancy, artificial intelligence is already making big ripples. The world’s biggest software companies have done a good job of injecting it into the software and devices we use most, and now they need to develop trust and show us why we should care.

The likes of ChatGPT and Q are useful tools whose programmed quest to pander and please can lead to them giving incorrect information. Copyright questions and the potential loss of true creatives to AI limitations are problems that must be ironed out, but the limitless possibilities of AI mean it’s here to stay.

Unleashing astonishing processing power with the ability to learn, adapt and problem solve will yield incredible results – as long as humans retain oversight. It’s already changing the world, and it’s not done yet.

See our investigation: Can you trust AI? ChatGPT and other AI chatbots tested, plus learn how to avoid AI scams.

12. Video streaming

When the clock struck midnight on 1 January 2000, most people in the UK had access to five TV channels. Fixed schedules, five options – with no swearing, violence or sex before 9pm. Streaming tore up these rules.

It was on-demand viewing. No schedule, no programme guide – just a catalogue of drama, documentaries and films only a search away. Even with Freeview bringing more channels, broadcast TV is a tuck shop with a few sweets, while streaming is Willy Wonka’s whole factory.

The cornucopia of choice catering to all tastes made streaming services some of the country’s biggest success stories. At 300 million, Netflix has more subscribers than there are people in the UK, France, Germany and Spain combined. Many rivals aren’t far off these figures, either.

Streaming was a significant part of the immediacy culture that defines the past 26 years. We want choice, and now.

See our guide to the best and worst TV streaming services to find out which one real customers think is best.

13. Nintendo Wii

Depending on who you ask, back in the day a video game controller was an intuitive conduit to fun or a barrier to entry. The collection of colourful buttons might as well have been a 747 cockpit to some, and it reinforced the idea that console gaming wasn’t for them. Nintendo, ever the innovator, saw this problem and fixed it.

While traditional controllers looked like Formula 1 steering wheels, the Wii controller had more in common with a TV remote. It felt familiar to all, even before Nintendo played its trump card. Wii Sports came packaged with every console, and it masterfully took advantage of the Wii’s headline feature: motion control.

The ‘Wiimote’, as it was known, became a tennis racket, a golf club, a bowling ball and more. The intuitive joy of seeing an avatar mirror your movements, whether smashing an ace or rolling in a strike, is a moment that broke down barriers and preconceptions decades in the making.

The Wii made gaming for everyone, and it went on to sell more than 100 million consoles.

See our pick of the best gaming deals covering Nintendo, PS5, Xbox and more.

14. Uber

'Should we get an Uber?' Pre-2012 this was a meaningless phrase, but an ingenious app and a fleet of Toyota Priuses made it common parlance. Its introduction has been far from smooth. From resisting drivers’ right to a minimum wage (until the Supreme Court ruled otherwise) to its effect on traditional taxi companies, Uber is controversial, but that hasn’t dulled its popularity.

Being able to see a fixed price for the journey and know the car's location on a map, as well as the name and face of a registered driver before you get in the car, gave Uber the edge over black cabs and local firms.

It spawned competitors, but no one’s saying 'should we get a Bolt?'. Uber is genericised: to many people it now means taxi; that's unlikely to change.

15. BBC iPlayer

The idea of appointment television – households gathering at a set time for a long-awaited series finale, phone off the hook, a chorus of shushes as the adverts end – is effectively over. Broadcasters once set the timetable, but not anymore. When the BBC launched its catch-up service in 2007, it put the viewer in charge of the schedule and was one of the early pebbles that became a streaming avalanche.

Unless you recorded TV onto video cassettes, DVDs or a PVR, you had no chance to watch a show. Evening plans, schedule clash, someone else using the TV? Sorry, you’ve missed it. It seems archaic now, as iPlayer gives you weeks to watch whatever you missed in your own time.

ITV, Channel 4 and Channel 5 soon followed suit, and catch-up TV was born. Amazing shows are still getting made, thrilling finales are still being discussed, but you make the appointment to watch.

Enjoy your favourite shows on a TV with dazzling picture quality – see our round-up of the best TVs to suit your budget.

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