Which iPhone is best? Or more specifically, which iPhone is best for you? Should you buy one of the newer iPhones - the iPhone 6 or the iPhone 6 Plus - or would an older model, such as the iPhone 5c or the iPhone 5s, be a better (as well as cheaper) option? Or perhaps it's worth waiting for the next generation, which - for want of confirmation from Apple - we're still referring to as the iPhone 6c, the iPhone 6s and the iPhone 7.

In this article we examine all the options for prospective iPhone buyers: the four models of iPhone currently available, the differences between them in terms of specs, design, features and price, and which one is right for each category of buyer. We also look at older models of iPhone, and advise owners of these iPhones what their best upgrade path is. Finally we talk about storage capacities and colour options.

Whatever you need to know about choosing your next iPhone, we've got the answer here.

Find out what might be coming in 2015:

iPhone 7 release date rumours

iPhone 6s release date rumours

iPhone 6c release date rumours

iPhone buying guide: Which iPhone is right for you?

Since the iPhone 6 and iPhone 6 Plus launched in September, you may have been wondering which iPhone to buy. Should you buy the 4.7-inch iPhone 6? Or might the even bigger 5.5-inch iPhone 6 Plus be more suited to your needs? Alternatively you might have an iPhone 5s or iPhone 5c and be wondering whether it's worth updating to the iPhone 6 or iPhone 6 Plus.

If your financial resources are somewhat limited, your decision may be based on just how much of a battering your wallet can take. The iPhone 6 Plus costs even more than the iPhone 6, which in turn costs more than the iPhone 5s and the iPhone 5c. If you're really strapped for cash that doesn't mean that you can't own an iPhone; there are various places you can get a second-hand handset, especially now that people are upgrading to the new models. You may be able to get a good deal on one of the older handsets if someone is looking to sell their current iPhone.

We'll evaluate all the iPhone handsets here in this article so you know what you are getting for your cash, including whether they will run the latest iPhone software. The more recent Apple iPhones will have access to most of the new features coming in iOS 8, and there will also be limited compatibility with some of Apple's older handsets.

Whatever the practical benefits of the new iPhone 6 and iPhone 6 Plus, you will have to weigh up whether those new features, and the pleasure of owning one of the very latest iPhones, are worth the extra expense.

If you've never owned an iPhone because they were too expensive for you, it may be possible to join the iPhone world with a relatively new Apple smartphone for less than £350 up front (and potentially for free on a monthly contract). 

You may have never owned an iPhone and be wondering whether to buy an iPhone or a Android or Windows smartphone. We will look at how the Apple iPhones compare to competitor phones from the likes of Samsung and Nokia. We will also look at how owning other Apple products, such as a Mac or an iPad, might enhance your iPhone experience if you purchase one.

Read on to find out everything you need to know about buying an iPhone.

iPhone buying guide: How to decide which iPhone to buy

Choosing the best iPhone for your needs depends on how you'll use the phone, which functions you'll want to use most often, and how much you are prepared to pay - although the price is relative as you may find a good deal on a network contract that allows you to spread payments in such a way as to allow you to afford the phone of your dreams. 

To help you decide which iPhone to buy, we've summarised the main differences between the various iPhones in the section below, but it's not quite as simple as weighing up the specs. Every Apple fan is different, and every Apple fan has different priorities. Perhaps you need as many gigabytes as you can get, maybe you are a keen iPhone photographer looking for the best iPhone camera, or perhaps you like to play games on your iPhone and need to make sure that the model you choose is up to the task. We aim to help you buy the best iPhone for you.

You can read our current iPhone reviews here:

iPhone buying guide: A quick history of the Apple iPhone

Before we start, here's a quick iPhone history to put Apple's smartphone in context.

The first iPhone launched in 2007. Apple actually unveiled it in January 2007, but it didn't launch until the end of June in the US, and November in the UK. The first ever iPhone didn't even offer 3G and it wasn't even the first smartphone, but it did reinvent smartphones and pretty soon after all the other mobile manufacturers started producing iPhone-like handsets with touchscreens and apps just like Apple's iPhone.

Apple has introduced a new iPhone (or two new iPhones) every year since 2007. The company has also updated the iPhone operating system - iOS - every year around the time the new iPhone launches. This means that anyone who owns an iPhone (or iPad) can update their device and enjoy many of the new features offered by the newest handsets.

iPhone buying guide: The full iPhone range (and which iPhone have you got?)

First things first. If you already own an iPhone, which iPhone do you have? This is an important question. If you already own an iPhone it is likely to influence your decision of which iPhone to purchase next. And if you have never owned an iPhone, your needs may be influenced by the Android or Windows smartphone that you have been using.

The iPhone models available currently are as follows:

iPhone 6 Plus

The new iPhone 6 Plus is Apple's first phablet-style phone. Phablet is basically the name used for phones that are so big that they are like small tablets. The iPhone 6 Plus has a 5.5-inch screen so it's not a lot smaller than the iPad mini. In addition to the bigger, better screen the Plus offers a better camera than the iPhone 6. Read our iPhone 6 Plus review.

iPhone buying guide: iPhone 6 Plus

Who is the iPhone 6 Plus best for? Those who want a 'phablet' experience - one which is midway between a phone and a small tablet. Big fans of gaming and movies, both of which look great on the 6 Plus's big screen. Some business users may find that the big screen is good for productivity apps. Early adopters and others who like to have the latest thing. Those on a big budget.

If you've got an iPhone 6 Plus... Then you're on the top-tier iPhone, so there's no need to upgrade! Of course, if you're finding the device a bit too big (and more than a few buyers have found this), then you might choose to downgrade to the smaller iPhone 6 or the still-smaller iPhone 5s.

iPhone 6

The iPhone 6 has a bigger screen than the iPhone 5s: 4.7 inches (measured diagonally, corner to corner) compared to 4 inches. It's also thinner and lighter than the previous year's model, and like the iPhone 6 Plus it features a better A8 processor and an NFC chip for mobile payments. Read our iPhone 6 review and our iPhone 6 vs iPhone 6 Plus comparison review.

iPhone buying guide: iPhone 6

Who is the iPhone 6 best for? Similar to the iPhone 6 Plus: those who would like a bigger screen (for games and films in particular, but also work apps and a generally more immersive experience) but want a more portable device. The iPhone 6 is easier to slip into a pocket (and easier to use one-handed) than the iPhone 6 Plus. It's also a bit more affordable.

If you've got an iPhone 6... Again, you're unlikely to be considering an upgrade, unless this taste of a larger screen has whetted your appetite for the even bigger iPhone 6 Plus. (And if you afford to buy an iPhone 6 and an iPhone 6 Plus in the space of a couple of months, any chance you could lend me a tenner?) Your next upgrade could be next year - Apple may release a new big-screen iPhone as part of the iPhone 7 series - but many iPhone owners upgrade every other year. It might make sense to hold on to the iPhone 6 until 2016.

iPhone 5s

This is the iPhone Apple introduced in September 2013. It's available in gold, silver or grey and has a Touch ID button allowing fingerprint scanning for security, rather than the older style home button with a square in the middle. The Touch ID button is the most obvious difference. It uses a Nano-SIM. Apple is now only selling only the 16GB and 32GB models. Read our iPhone 5s review. and our iPhone 5s vs iPhone 6 comparison review.

If you've got an iPhone 5s... The main question is this: should you upgrade to the iPhone 6 or iPhone 6 Plus?

Apple's iPhone evolution usually allows owners to skip a generation without too much worry, but the new bigger screen on the iPhone 6 and iPhone 6 Plus will be a big temptation for many iPhone 5s owners. The big question will be whether to go for the iPhone 6, with its 4.7in screen, or the iPhone 6 Plus with its 5.5in screen.

If you really don't feel the need for a bigger screen then there is no harm in skipping a generation. Apple may one day update the iPhone 5s with a faster processor and other features, but keep the same screen size.

If you decide to upgrade your phone you could sell your current iPhone 5s and get a reasonable price for it, which will no doubt help with the cost of the new iPhone.

New features offered by the iPhone 6 Plus that aren't in the iPhone 5s:

  • Retina HD display
  • 5.5-inch display (compared to 4-inch)
  • 1920-by-1080 pixel resolution at 401ppi (compared to 1136-by-640-pixel resolution at 326 ppi)
  • 1300:1 contrast ratio (compared to 800:1 contrast ratio)
  • Dual-domain pixels for wider viewing angles
  • Display Zoom
  • Reachability
  • A8 & M8 chips (compared to A7 & M7)
  • Autofocus with Focus Pixels
  • Optical image stabilization
  • Improved face detection
  • Panorama, up to 43 megapixels
  • 1080p HD video recording, 30 fps or 60 fps (was 30 fps)
  • Slo-mo video, 120 fps or 240 fps (was 120 fps)
  • Cinematic video stabilization
  • Continuous autofocus video
  • Improved face detection on both cameras
  • ƒ/2.2 aperture for FaceTime camera (compared to ƒ/2.4 aperture)
  • Auto HDR for photos and videos on FaceTime camera (previously Auto HDR only)
  • Burst mode on FaceTime camera
  • Pay with your iPhone using Touch ID in stores and in apps
  • 802.11ac Wi-Fi
  • NFC
  • FaceTime over cellular uses H.264/H.265
  • Voice over LTE (VoLTE)3
  • Up to 24 hours talk time on 3G (was 10)
  • Up to 16 days/384 hours standby time (was 10 days, 250 hours)
  • Up to 12 hours internet on 3G, up to 12 hours on LTE, and up to 11 hours on Wi-Fi (was 8 , 10 and 11)
  • Up to 14 hours video playback (was 10)
  • Up to 80 hours audio playback (was 40)
  • Barometer

New features offered by the iPhone 6 that aren't in the iPhone 5s:

  • Retina HD display
  • 4.7-inch display (compared to 4-inch)
  • 1334-by-750 pixel resolution at 326ppi (compared to 1136-by-640-pixel resolution at 326 ppi)
  • 1400:1 contrast ratio (compared to 800:1 contrast ratio)
  • Dual-domain pixels for wider viewing angles
  • Display Zoom
  • Reachability
  • A8 & M8 chips (compared to A7 & M7)
  • Autofocus with Focus Pixels
  • Improved face detection
  • Panorama, up to 43 megapixels
  • 1080p HD video recording, 30 fps or 60 fps (was 30 fps)
  • Slo-mo video, 120 fps or 240 fps (was 120 fps)
  • Cinematic video stabilization
  • Continuous autofocus video
  • Improved face detection on both cameras
  • ƒ/2.2 aperture for FaceTime camera (compared to ƒ/2.4 aperture)
  • Auto HDR for photos and videos on FaceTime camera (previously Auto HDR only)
  • Burst mode on FaceTime camera
  • Pay with your iPhone using Touch ID in stores and in apps
  • 802.11ac Wi-Fi
  • NFC
  • FaceTime over cellular uses H.264/H.265
  • Voice over LTE (VoLTE)3
  • Up to 14 hours talk time on 3G (was 10)
  • Up to 10 hours internet on 3G, up to 10 hours on LTE, and up to 11 hours on Wi-Fi (was 8 , 10 and 11)
  • Up to 11 hours video playback (was 10)
  • Up to 50 hours audio playback (was 40)
  • Barometer

iPhone 5c

The iPhone 5c has a polycarbonate (plastic) shell that comes in six bright colours. Apple released the iPhone 5c alongside the iPhone 5s in September 2013. On the inside it's pretty similar to the iPhone 5, although the camera is better. It uses a Nano-SIM. Read our comparison review of the iPhone 5s versus the iPhone 5c. This model is now only available in 8GB. Read our iPhone 5c review.

If you've got an iPhone 5c... You may be wondering if you should upgrade to the iPhone 6 or iPhone 5s.

If last year you bought the iPhone 5c you would actually see a boost if you updated to the iPhone 5s now, because the processor is faster in that model. There are various other features that the iPhone 5s has that the iPhone 5c doesn't, like the Touch ID fingerprint scanner and a better camera with better photography features. Apple has dropped the price of the iPhone 5s compared to last year, so you could find it is more affordable now than it was. 

Last year the iPhone 5s cost £549 for the 16GB version, £629 for the 32GB version, and £709 for the 64GB version. Now it costs £459 for the 16GB and £499 for the 32GB. That's £130 less for the 32GB version. You may also be able to pick up a good deal on a second hand iPhone 5s.

However, if you want to upgrade to the new iPhones with their bigger screens then at least if you sell your existing iPhone 5c you should get a reasonably good price for it.

New features offered by the iPhone 6 that aren't in the iPhone 5c

  • Retina HD display
  • 4.7-inch display (compared to 4-inch)
  • 1334-by-750 pixel resolution at 326ppi (compared to 1136-by-640-pixel resolution at 326 ppi)
  • 1400:1 contrast ratio (compared to 800:1 contrast ratio)
  • Dual-domain pixels for wider viewing angles
  • Display Zoom
  • Reachability
  • A8 & M8 chips (compared to A6)
  • Autofocus with Focus Pixels
  • Improved face detection
  • Panorama, up to 43 megapixels
  • 1080p HD video recording, 30 fps or 60 fps (was 30 fps)
  • True Tone Flash (LED flash)
  • Slo-mo video at 120 fps or 240 fps (5c didn't have slow-mo video)
  • Cinematic video stabilization
  • Continuous autofocus video
  • Improved face detection on both cameras
  • ƒ/2.2 aperture for FaceTime camera (compared to ƒ/2.4 aperture)
  • Auto image stabilization
  • Auto HDR for photos on both cameras (was just HDR)
  • Auto HDR for video on FaceTime camera
  • Burst mode
  • Burst mode on FaceTime camera
  • Pay with your iPhone using Touch ID in stores and in apps
  • 802.11ac Wi-Fi
  • NFC
  • FaceTime over cellular uses H.264/H.265
  • Voice over LTE (VoLTE)3
  • Up to 14 hours talk time on 3G (was 10)
  • Up to 10 hours internet on 3G, up to 10 hours on LTE, and up to 11 hours on Wi-Fi (was 8 , 10 and 10)
  • Up to 11 hours video playback (was 10)
  • Up to 50 hours audio playback (was 40)
  • Barometer

Features offered by the iPhone 5s that aren't in the iPhone 5c

  • A7 & M7 chips (compared to A6)
  • True Tone Flash (LED flash)
  • Slo-mo video at 120 fps
  • Auto HDR for photos on FaceTime camera
  • Burst mode

iPhone 5 (currently not on sale)

The iPhone 5 was launched in September 2012 and was the first Apple iPhone with a 4in screen. It was available in 'Slate' or 'Silver'. The iPhone 5s looks similar to the iPhone 5, but the clearest difference between the two iPhones is the home button which has a white square logo in the centre on the older iPhone. It uses a Nano-SIM. Read our iPhone 5 vs iPhone 5S comparison review our iPhone 5 review, and our iPhone 5c v iPhone 5 comparison review.

If you've got an iPhone 5... With a device that's now just over two years old, you're probably thinking about upgrading. But if you decide to trade in your iPhone 5 for another iOS device, should you upgrade to the iPhone 6 Plus, iPhone 6, iPhone 5s or iPhone 5c?

For a start, if you're still using an iPhone 5 you may be missing out on 4G, as that model only supports 4G on a few of the UK networks (basically EE). If you are with one of the networks that isn't supported for 4G, O2, Vodafone, for example, faster mobile broadband on the go is a great reason to upgrade. Find out if your network is supported here.

Since you may have had this phone for two years now it is likely you are coming to the end ouf your contract, which means it's an excellent time to upgrade. Plus you can sell your iPhone 5 and potentially get some money to put towards a new iPhone.

You don't have to pay a huge amount to upgrade from the iPhone 5 to the iPhone 5c, the iPhone 5c is now Apple's cheapest iPhone costing £319 up front (and probably available for free on contracts).

However, there isn't a big difference between the iPhone 5c and the iPhone 5, in fact when it launched many pointed out that the iPhone 5c is a repackaged iPhone 5. However, apart from the obvious difference - colour and polycarbonate coatings - the iPhone 5c does offer a better camera and, as we said above, it will work with all the UK 4G networks.

The one place where the iPhone 5c lets itself down is the capacity - Apple is only offering 8GB which really isn't enough in our opinion.

On that basis, it might be better to update from the 5 to the 5s, or go the whole hog and get the iPhone 6 or 6 Plus. 

iPhone 4s (currently not on sale)

Apple was still offering the iPhone 4s for sale until quite recently, but it dropped out of availability when the iPhone 6 series made their debut. There are still a fair few Apple fans on this relatively elderly device.

The iPhone 4s has a smaller screen than the iPhone 5 (it's just 3.5 inches, compared to the 4-inch screens on the iPhone 5, 5c and 5s, and of course the still-bigger screens on the iPhone 6 series) but has a similar metallic shell. It uses a Micro-SIM and was launched in October 2011. Read our iPhone 4s review and our iPhone 5c vs iPhone 4s review.

If you've got an iPhone 4s... should you update to one of the newer iPhones?

Upgrading from the iPhone 4s is a bit of a no-brainer. It's a 3.5-inch phone for starters, so you're working with less screen than most other smartphone owners: whether you upgrade to the iPhone 5c or 5s for a 4-inch screen, or the new iPhones with their 4.7-inch or 5.5-inch screens, you'll quickly get used to the extra screen space. The iPhone 5 was 18 percent thinner and 20 percent lighter than the 4S, the iPhone 5s even lighter still. The new iPhones are even thinner, although since they have bigger screens you may notice the extra bulk.

For some the huge leap from a 3.5in iPhone to a 4.7in (or even 5.5in) model may be too great. Those people might prefer to opt for the cheaper iPhone 5s.

The only other reason that you may not wish to upgrade from the iPhone 4s is if you own speakers and other iPhone accessories that use the older iPhone port. With the iPhone 5 Apple introduced the smaller Lightning dock, which means your existing accessories will need an adaptor, which costs £25.

However, we find these days that many of the stereo systems use AirPlay rather than plugging in directly, and we don't really miss our old iPhone accessories.

In terms of iOS 8, bear in mind that the iPhone 4s misses out on some of the showier improvements.

iPhone 4 (currently not on sale)

The iPhone 4 looks very similar to the iPhone 4s, and like that model it uses a Micro-SIM. The key difference is the number of megapixels offered by the camera: 5Mp in the iPhone 4 compared to 8Mp in the iPhone 4s. It launched in June 2010. Read our iPhone 4 review.

iPhone buying guide: iPhone 4

If you've got an iPhone 4... If you're still using an iPhone 4 then now is a good time to upgrade. Whichever of the four currently available iPhones you choose will add a bigger screen, thinner chassis and 4G capabilities. The iPhone 4 is well behind both 4S and 5 in its photographic fidelity and has no Siri voice assistant. It's also about a quarter as fast as the iPhone 5 so imagine how much faster the new iPhone 6 will be.

In terms of iOS 8, bear in mind that the iPhone 4 will not be supported so you will be left behind in terms of new features and other improvements that will come with the new operating system - including new features coming in Mac OS X Yosemite that will make your Mac, iPhone and iPad work together.

iPhone 3Gs (currently not on sale)

The iPhone 3Gs was the last of Apple's plastic iPhones for several years (the company eventually returned to plastic shells for the iPhone 5c). It had a 3Mp rear-facing camera but no front-facing camera for FaceTime. Like the 3G, this model came in black or white. It launched in June 2009. Read our iPhone 3GS UK review.

If you've got an iPhone 3GS (or an earlier iPhone model)... A lot of people are still happily using an iPhone 3GS. Perhaps they adopted one when a family member updated their iPhone. They have missed out on iOS 7 and more recently missed out again on iOS 8, so for the sake of new software features alone it may be time to update.

There's no need to jump right up to the iPhone 6 in this case, of course. The cheaper iPhone 5c may well suit you, and you could probably pick one up for a good price on eBay or similar.

Whatever you update to, you will enjoy a Retina display, a marvel of touchscreen technology with pixels so closely packed they can fool the human eye, and a far cry from the 3GS.

iPhone 3G (currently not on sale)

The iPhone 3G had a 2MP camera and no front-facing camera. This model came in black or white. It launched in July 2008. Read our iPhone 3G review.

iPhone (currently not on sale)

Launched in June 2007, the original iPhone had a 2Mp camera. The first iPhone was only available in a black plastic finish. Read our iPhone (first-generation) review.

We have a complete rundown on every iPhone ever made by Apple here: Which iPhone: Every iPhone compared

Watch our video comparing the iPhone 5s, 5c, 5, 4s, 4 and every iPhone ever made. We'll be creating a similar video including the new iPhone 6 and iPhone 6 Plus.

iPhone buying guide: How much should you spend on an iPhone?

We tend to recommend that consumers spend as much money as they can upfront when buying an iPhone. There are a few reasons why. Firstly if you don't get enough GB at the start then you may feel crippled later - there is no way to add more memory at a later date and no SD card slot like you will find on some Android phones. We address the question of how many GB of storage you need further down in this article.

Remember when you look at the price of the iPhone as offered by Apple that this is the price if you buy the iPhone outright. You don't have to fork out a lot upfront if you sign up for a contract with one of the UK networks. Of course this means that you will have a higher monthly bill than you would if you were only paying for the minutes and data, but for most people who don't have thousands in their rainy day account, this may be the best choice.

We think the best idea is to find a happy medium. Look for a good network contract that means you won't be paying a hell of a lot over time. Always times the monthly bill by 24 if it's a two year contract or 12 if it's a one-year contract and add the up front cost to see what kind of a deal you are signing up for. It may look like a good deal, but it is all relative.

The phones that Apple sells currently are priced as follows on Apple's website, although as we keep saying, these are unlocked, non-contract prices, so you can spread payments over two years if you want to sign up with a network.

  • iPhone 5c: 8GB, £319
  • iPhone 5s: 16GB, £459 | 32GB, £499
  • iPhone 6: 16GB, £539 | 64GB, £619 | 128GB, £699
  • iPhone 6 Plus: 16GB, £619 | 64GB, £699 | 128GB, £789

You can read more about the contract pricing of the iPhones here: iPhone 6 Plus release date and pricing and iPhone 6 release date and UK pricing.

iPhone buying guide: What is the best screen size for an iPhone?

There are three different screen sizes of iPhone available currently: 4-inch, 4.7-inch and 5.5-inch. That's a far cry from Apple's insistence that it wouldn't make an iPhone with a bigger screen because of "tradeoffs in screen quality", and because it is less comfortable and ergonomic to use a bigger screen. (Apple has previously emphasised the fact that the 4in screen is ideal because you can use it one-handed.)

Both of the new iPhones are larger than the 4-inch screen on last year's flagship iPhone, but Apple has made sure that the new iPhones are still comfortable to use despite the bigger surface area. For example, to compensate for the larger screen sizes, Apple's engineers have implemented a feature called Reachability. Reachability is activated by a double-touch on the Home button and it shrinks the user interface towards the bottom of the phone and closer to your thumb. This makes it easier to tap objects near the top of the screen while using one hand.

iOS 8 has also been designed to take advantage of the larger screens so, for example, the keyboard on the Plus has extra keys, including dedicated virtual buttons for cut, copy and paste. And, also on the Plus, apps like Messaging, Email, and Calendar use a split mode to show you more information.

The best screen size is likely to be a very personal thing. Perhaps you have small hands and the 5.5in iPhone 6 Plus would dwarf them. Perhaps you tend to use your iPhone most while commuting to and from work and having to use it one-handed means that even with Apple's Reachability features it would be uncomfortable to use a big screened iPhone. Or maybe you have been waiting for the bigger screen since you saw your Android wielding friends with there's and feel that at last you can enjoy the benefits of a bigger screen.

There are various apps that will benefit from the bigger screen. Maybe you primarily use your iPhone for reading articles or watching movies - the bigger screen will be ideal. If you often find yourself tapping out work related documents and emails on your iPhone the extra space - and particularly the extra keys for the keyboard will be handy. On the other hand, if you already own an iPad you may not need a bigger iPhone too.

iPhone buying guide: Which iPhone has the best display?

As we mentioned earlier, the iPhone 6 Plus has a 1920-x-1080-pixel 5.5-inch LED-backlit display offering 401 pixels per inch.

The iPhone 6, on the other hand, offers a 1334-x-750-pixel LED-backlit display. Despite the fact that the display measures 4.7-inch, it works out to 326 pixels per inch, which is the same as the iPhone 5 and 5s.

Apple calls these new iPhones Retina HD display even though only the Plus offers a greater number of pixels per inch. in fact it offers two million pixels in total, that's nearly a million more pixels than the iPhone 6. However, both the new displays feature an LCD with dual-domain pixels for improved viewing angles and a substantially higher contrast ratio, so the iPhone 6 screen is still better than the iPhone 5s.

It's the contrast ratio that provides the biggest difference: last year's flagship iPhone 5s had an 800:1 ratio. This year the iPhone 6 has a 1400:1 ratio, and the larger 6 Plus offers 1300:1.

The iPhone 6 Plus offers 88% more viewing area and three times the pixels on iPhone 5/5s.

It sounds impressive, but remember, while the iPhone 6 Plus packs a million more pixels into the display, but there comes a point where we can't actually distinguish any difference - these displays are referred to as Retina Displays because there are only so many pixels your eye can see.

iPhone 6 Plus screen:

  • Retina HD display
  • 5.5-inch display (compared to 4-inch)
  • 1920-by-1080 pixel resolution at 401ppi
  • 1300:1 contrast ratio
  • Dual-domain pixels for wider viewing angles

iPhone 6 screen:

  • Retina HD display
  • 4.7-inch display (compared to 4-inch)
  • 1334-by-750 pixel resolution at 326ppi
  • 1400:1 contrast ratio
  • Dual-domain pixels for wider viewing angles

iPhone buying guide: What storage capacity to go for, and how many GB is best for an iPhone

Prior to the launch of the iPhone 6, iPhones tended to come in 16GB and 32GB versions, with a 64GB version available for the top of the range model. Apple has also been known to offer an 8GB on the most affordable iPhone. Read about why it's not a good idea to buy the 16GB version: The problem with Apple's 16GB iPhones and iPads

The current line up is slightly different:

The iPhone 6 and iPhone 6 Plus are available in 16GB, 64GB, and 128GB.

The iPhone 5s comes in 16GB and 32GB.

And the iPhone 5c comes in 8GB.

How do you decide how many gigabytes are necessary?

Apps are getting larger, and photos and videos are addictive to shoot and gobble up and ever-increasing amount of gigabytes. For that reason, as we mention above, we would always recommend going for as many GB as you can afford.

If you already have an iPhone check how much space all your apps and data are eating up on your by looking at Settings > General > Usage.

You don't have to transfer every app to your new iPhone though. We went from a 64GB to a 16GB without too much stress because we culled our apps. You can always download an app again at a later date, Apple knows that you already bought it so you can download it again for free.

Then again maintaining 16GB of space requires a lot of housekeeping, so if you take a lot of photos, or download video from iTunes or iPlayer, expect to fill up the space available quickly.

In the past we'd have recommended opting for 32GB over 16GB - we used to think that 64GB was overkill - but for some even 64GB may still not be enough, and they are the people who will be pleased with the option of a 128GB iPhone.

We think that the 8GB for the iPhone 5c is too small - we'd recommend looking for a second hand iPhone 5c with at least 16GB or 32GB as we think that it would be very difficult to manage with just 8GB given that iOS would take up a significant part of that space. We think that 8GB isn't really enough storage for the average iPhone user so we'd advice against the iPhone 5c for that reason.

We are disappointed that Apple is not selling a 32GB version of the iPhone 6 and iPhone 6 Plus - we think the best line up would be 32, 64, 128GB. However, it's likely that Apple is aiming to make the 64GB version an attractive upgrade from the 16GB entry-level model. It only costs £80 more, why wouldn't you spend the extra for all that extra storage.

Which iPhone is lightest? Weight and dimensions of Apple's iPhones

The larger screen obviously means a larger size and a bit more weight, so if you are looking for a lighter phone the 5.5-inch iPhone 6 Plus may not be the one for you. Similarly, if you have small hands you may find that the iPhone 6 Plus is too large to be held comfortably in your hand.

Even the iPhone 6, though thinner than the iPhone 5s, weighs more than that model. But that's hardly surprising given the fact that there is a greater surface area.

The weight and dimensions of the full range of iPhones currently on sale from Apple is as follows:

  • iPhone 6 Plus: 158.1 mm x 77.8 mm x 7.1 mm | 172 grams
  • iPhone 6: 138.1 mm x 67.0 mm x 6.9 mm | 129 grams
  • iPhone 5s: 123.8 mm x 58.6 mm x 7.6 mm | 112 grams
  • iPhone 5c: 124.4 mm x 59.2 mm x 8.97 mm | 132 grams

If portability is the key, and if you already own a tablet or use a traditional computer for everyday tasks you may not need a bigger screen iPhone.

Even if you could use a bigger screen you may not need the iPhone 6 Plus - the iPhone 6 screen is still 38 percent larger than the iPhone 5.

We think it's a shame that Apple is only offering new iPhones in these bigger sizes, we hope that in the future the company will upgrade the smaller 4in iPhones. Perhaps an iPhone 7 mini could arrive next year.

iPhone buying guide: iPhone colour choices

The iPhone 6, iPhone 6 Plus and the iPhone 5s all offer the same colour choices: silver (white), gold and space grey (black).

Only the iPhone 5c comes in bright colour choices. Choose from white, pink, yellow, blue and green.

Of course the colour choice may be redundant if you choose to put your iPhone in a case as many do, in order to protect them.

We have a round up of iPhone 6 and iPhone 6 Plus cases here: Best cases for iPhone 6: 14 iPhone 6, iPhone 6 Plus cases

iPhone buying guide: Which iPhone is best for software?

iOS 8 will work on the latest iPhones including the iPhone 5s, 5c, 5 and iPhone 4s as well as the new iPhone 6 and iPhone 6 Plus (obviously). Read about which iPhones will run iOS 8 here.

There are various new features coming in iOS 8 which will enhance existing iPhones as well as the new iPhones. We're particularly excited about Continuity, Widgets, new tools in Mail and Messages, the new keyboard features. Read more about what you can expect from iOS 8 here: iOS 8 beta review.

If you’re excited by iOS 8 but you’re willing to sacrifice a few features the iPhone 4s might be ok, but you need to keep in mind that that phone will be able to utilise many of the new features to their full potential and installing the new software may render your phone slower and less responsive. (Read about why Apple isn't making your iPhone slower on purpose)

It can be a whole lot worse than the iPhone 4s software situation though. Many of the features that came with iOS 6 back in 2012 don't even work with the iPhone 4. The main things missing are Siri, FaceTime over 3G, Flyover and turn-by-turn navigation. That phone won't even run iOS 8. 

You can also expect some of the older iPhones not to offer support for newer apps. Developers had been focusing efforts on four-inch iPhones,,  we expect that they will now focus their attention on the screen size of the new iPhones.

iPhone buying guide: Which iPhone is best for photography?

None of today's cameraphones can replace a digital SLR for top-level photography, but iPhones are definitely getting better in this area. Over the iOS iterations we've gained a panoramic shooting mode, burst mode, slow-mo video recording, and various editing features. There are even more new camera features coming with iOS 8. Read about the best new camera features coming in iOS 8.

The iPhone 5s, iPhone 5c and iPhone 5 all offer 8 megapixels. There were rumours that the new iPhones would offer more megapixels but they don't. Find out why that doesn't matter, and why megapixels aren't everything, in this article: Why it doesn't matter how many megapixels your iPhone has.

What the new iPhones do offer is improvements in the camera software. The iPhone 6 Plus features a camera with optical stabilisation, which should help in taking pictures and video. While the iPhone 6 offers an improved camera with digital stabilisation.

When Apple launched the iPhone 5s they made much of the fact that sensor size is more important than the number of megapixels. When Apple launched that iPhone, rather than make the pixels smaller in order to increase the amount of pixels that can be fitted on the sensor, Apple increased pixel size to 1.5µm (from 1.4µm - those measurements are in micrometers) and kept the pixel count the same by using a 15 percent larger sensor. The new iPhones also offer these bigger pixels for better pictures.

Another new feature in the iPhone 5s was a True Tone Flash which was designed to make flash photography more flattering.

New camera features offered by the iPhone 6 Plus

  • Autofocus with Focus Pixels
  • Optical image stabilisation
  • Improved face detection
  • Panorama, up to 43 megapixels
  • 1080p HD video recording, 30 fps or 60 fps (was 30 fps)
  • Slo-mo video, 120 fps or 240 fps (was 120 fps)
  • Cinematic video stabilisation
  • Continuous autofocus video
  • Improved face detection on both cameras
  • ƒ/2.2 aperture for FaceTime camera (compared to ƒ/2.4 aperture on iPhone 5s)
  • Auto HDR for photos and videos on FaceTime camera (previously Auto HDR only)
  • Burst mode on FaceTime camera

New camera features offered by the iPhone 6

  • Autofocus with Focus Pixels
  • Improved face detection
  • Panorama, up to 43 megapixels
  • 1080p HD video recording, 30 fps or 60 fps (was 30 fps)
  • Slo-mo video, 120 fps or 240 fps (was 120 fps)
  • Cinematic video stabilisation
  • Continuous autofocus video
  • Improved face detection on both cameras
  • ƒ/2.2 aperture for FaceTime camera (compared to ƒ/2.4 aperture on iPhone 5s)
  • Auto HDR for photos and videos on FaceTime camera (previously Auto HDR only)
  • Burst mode on FaceTime camera

Camera features offered by the iPhone 5s that aren't in the iPhone 5c:

  • True Tone Flash (LED flash)
  • Slo-mo video at 120 fps
  • Auto HDR for photos on FaceTime camera
  • Burst mode

iPhone buying guide: Which iPhone is best for battery life?

The iPhone 6 Plus model has a larger battery than any other iPhone which means Apple can claim a talk time of up to 24 hours on 3G and a standby time of 16 days compared to the iPhone 6's 14 hours and 10-day standby.

Video and audio playback as well as internet use is listed as 14, 80 and 12 hours on the Plus; 11, 50, and 10 hours on the 6. if you spend a lot of time using your phone to read, surf or check email and Facebook, the larger screen and longer battery life are a better option.

iPhone 6 Plus battery life

  • Up to 24 hours talk time on 3G
  • Up to 16 days/384 hours standby time
  • Up to 12 hours internet on 3G, up to 12 hours on LTE, and up to 11 hours on Wi-Fi
  • Up to 14 hours video playback
  • Up to 80 hours audio playback

iPhone 6 battery life

  • Up to 14 hours talk time on 3G
  • Up to 10 hours internet on 3G, up to 10 hours on LTE, and up to 11 hours on Wi-Fi
  • Up to 11 hours video playback
  • Up to 50 hours audio playback

iPhone 5s battery life

  • Up to 10 hours talk time on 3G
  • Up to 8 hours internet on 3G, up to 10 hours on LTE, and up to 10 hours on Wi-Fi
  • Up to 10 hours video playback
  • Up to 40 hours audio playback

iPhone 5c battery life

  • Up to 10 hours talk time on 3G
  • Up to 8 hours internet on 3G, up to 10 hours on LTE, and up to 10 hours on Wi-Fi
  • Up to 10 hours video playback
  • Up to 40 hours audio playback

iPhone buying guide: Which iPhone is best for watching movies on the go?

For film fans, we recommend the iPhone 6, iPhone 6 Plus, iPhone 5, 5c or 5s because the widescreen display - with its 16:9 aspect ratio - is ideal for a mini-cinematic experience. The older iPhones with their smaller 3.5in displays (aspect ratio of 3:2) don't suit widescreen viewing very well.

Bear in mind that movies will quickly fill up storage, so the 64GB and 128GB models are probably worth the extra investment, although you can purchase a separate Wi-Fi storage device that you can use with your iPhone.

iPhone buying guide: Which iPhone is best for games?

This one depends on what kind of games you like. If processor-intensive graphical feasts like Infinity Blade are your thing - and if you intend to keep playing the latest games in the future - then the faster A8 processor with 64-bit support in the iPhone 6 and iPhone 6 Plus will be worth the price of admission.

However the A7 chip (also 64-bit) in the iPhone 5s is no slouch when it comes to gaming.

The App Store will contain games that run only on the iPhone 5s or even newer iOS hardware. If you love to play the newest, best-of-breed games, you may well miss out on those titles - or at least their full feature-set and performance abilities - unless you upgrade to Apple's top-of-the-line phone.

Our experience suggests that at least 32GB of storage is advisable for heavy gamers, although you can get by with less if you're willing to focus on a few games at a time, and uninstall them once you're finished. 

Read more in our best iPhone and iPad games feature.

iPhone buying guide: Which iPhone is best for business users?

Unless you’re desperate to show off the latest iPhone while networking, or are big fans of gaming and movies in their spare time, business users can probably get by with an earlier model; a super-fast processor will be wasted if your principal needs are email, contacts management and light browsing. 

However, the extra screen space is likely to prove useful if you are trying to produce documents and do other work on your iPhone and you don't already own an iPad. There are also some handy features on later iPhone models, such as the ability to make FaceTime calls over 3G and videoconference when outside Wi-Fi range: a handy option for the business-inclined.

iPhone buying guide: Which iPhone is best for sporty types?

If you already own a fitness monitor, or you are thinking of buying the Apple Watch (read: Apple Watch rumours, release date & images and our Apple Watch first look review), you may want to stick with an iPhone 5s or later, although Apple says that the iPhone 5c will support the Apple Watch.

Apple introduced the M7 "motion coprocessor" chip with the iPhone 5s in 2013 and this chip works in sequence with a fitness monitor to track the data without over using the battery in your iPhone. The new iPhone 6 and iPhone 6 Plus both offer an M8 chip. There is also a new Barometer included inside the phone - for blood pressure, not for telling what the weather will be like.

All Apple's iPad and iPhone models ship with iOS 8 and various apps provided by Apple for free. There are also thousands of apps available on the Apple App Store for you to download. Here are the 10 best apps for your new iPad or iPhone to get you started.