Apple's latest version of the iPhone and iPad operating system, iOS 11 launched on 19 September 2017. But, assuming your device is new enough to make the upgrade (check our list of compatible phones and iPads here), is it a good idea to install the new software on your iPhone or iPad?

In this article we weigh up the pros and cons of updating iOS on your iPhone or iPad, and help you decide whether to upgrade to iOS 11 or stick with iOS 10 or earlier.

New features in iOS 11

Each new version of iOS brings a bunch of new features, and iOS 11 has an impressive roster. Bear in mind, however, that many of its most dramatic enhancements are for the iPad only.

If you're on iPhone you get: a redesigned and reorganised App Store, lots of new features in Messages including peer-to-peer Apple Pay and a new one-handed keyboard, a more intelligent and natural-sounding Siri, new animated emoji, a built-in QR scanner, new effects and editing tools in Live Photos, a new feature called Do Not Disturb While Driving, to name a few.

On iPad you get all the above, plus a new Dock interface feature, drag-and-drop of images etc between two apps in splitscreen, a boring but extremely useful new app called Files and improved Apple Pencil support.

Pro: We think the new features you will get in iOS 11 are a good reason to update. 

Should I update to iOS 11?

Check out iOS 11 vs iOS 10 for a direct comparison between iOS 11 and its predecessor.

Design changes

There are some graphical tweaks in this version of iOS including updated app icons and some new transition effects, such as the way that when you close an app the Home Page appears to zoom into view.

We particularily like the redesigned Control Centre, which now appears on a single screen making it much quicker to get to the tools you need. We particularly like the sliders for changing the volume and brightness.

However, not everyone likes change. When iOS 7 launched, many users were horrified by the radical graphical redesign, which took a while to get used to and still annoys a minority of iPhone and iPad owners. That year we advised people to spend time with borrowed iOS 7 devices if they could, and see if they got used to the look of the OS after a week or two - generally interface changes feel earth-shattering at the time, then before you know it you can't remember how it used to look.

While the changes in iOS 11 aren't quite as radical as those in iOS 7, iOS 11 will take a bit of getting used to, with a few things moving around in the interface. Aesthetically it's mostly the same as iOS 10 though, so we don't expect this to register as a serious downside.

Pro-ish: So while we are looking to turn off some of these transition effects in iOS 11, some of the design changes are good, and the others won't rock your boat quite as much as the transition to iOS 7 did, and we reckon you will get use to them quickly.

Going back is difficult (or impossible)

Here's a potential reason not to update: upgrading iOS tends to be essentially a one-way journey. It's always extremely hard (if not impossible) to go back to the previous version of iOS afterwards, so be sure you want to do this before starting the upgrade process.

It's very difficult to reinstall a version of iOS once Apple stops 'signing' (or verifying) it, and the company will stop signing versions of iOS 10 a few days after the launch of iOS 10. You'll have a tiny window to go back, and even then it'll be tricky. It's generally best to assume that you'll be stuck with the new OS if you update.

Our advice is to wait a few weeks before taking the plunge if you aren't sure you will take to it. Maybe borrow a friend's iPhone and try it out on there.

Con: If you don't like change it's best to avoid this upgrade because you won't be able to go back to iOS 10 if you hate it

Will updating iOS slow down my device?

When Apple announces a new version of iOS, it also announces the list of devices that are certified as capable of running it. For iOS 11, that's the following devices:

  • iPad Air 1, iPad Air 2, iPad Pro (12.9, 2015), iPad Pro (9.7, 2016), iPad (9.7, 2017), iPad Pro (10.5, 2017), iPad Pro (12.9, 2017)
  • iPad mini 2, iPad mini 3, iPad mini 4
  • iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, and iPhone X (when it launch in November)
  • iPod touch (sixth generation)

If your device isn't on that list, your decision is easy: you're not able to update. And if you've got one of the newer ones on there, again, it's a straight shoot-out - do you want the new features and the new graphical look, or not?

If you have one of the newer devices you can expect that it will perform even better once you have installed iOS 11. The iPad, in particular, is gaining a speed boost from the update with better multitasking capabilities.

The complication arises if you've got one of the borderline cases. One of the older devices that only just makes it on to the list. The iPhone 5s, for example, or the iPad mini 2.

Reports are indicating that the iPhone 5s - the oldest iPhone to support iOS 11 - is taking a mild speed hit from iOS 11.

However, it is suggested that this performance hit is less than the one experience by iPhone 5 users when they switched to iOS 10, or the iPhone 4S when updated to iOS 9. 

But if you've got a phone or tablet near the older end of the list above, we'd still advise caution.

Wait a few days after the launch to see if you can find out how the update for people with the same iPhone or iPad as you. Googling the name of your device and iOS 11 together is a good way to see what others users have experienced. If possible you could also try to find someone else running the same hardware with iOS installed and see how they got on - has their device slowed down at all?

Con: If you have an old iPhone... But not as much as it used to be.

Pro: If you have a new iPhone iOS 11 will not slow your device down.

Security

Security and performance patches come with any new version of iOS - including incremental updates, and it's usually a good reason to agree to the update.

Apple outlines some of the secuity enhancements in iOS 11 here. But there are two very significant new security features: the Emergency SOS setting and Do Not Disturb While Driving.

Emergency SOS is a feature that will let you lock down the iPhone so that people cannot hack in to it by forcing you to unlock the phone with your fingerprint. It could also be used to stop the Police from accessing your phone if you are a criminal type. We have this tutorial on how to use the Emergency SOS feature.

The Do Not Disturb While Driving feature could save your life as it will help avoid distractions when you are driving. The feature is able to recognise when you are in moving in a car and will enable itself automatically so that the phone won't ring and you won't get text message alerts, for example. More on that feature here: How to use Do Not Disturb When Driving

Pro: We think these new features are worth installing iOS 11 for, although you may want to be disturbed when driving...

Conclusions

If your iPad or iPhone is up to it (and really up to it - not just officially rated as iOS 11-compatible), you should probably update. Even if you don't care about the new features, the boring stuff - such as bug fixes and compatibility with new apps - is important.

But take the decision carefully, because you probably won't be able to go back.

See where your iPhone or iPad sits on the chart of compatible devices above. If it's only just new/powerful enough to run the new OS, you need to find out if there will be any speed problems. See how people with the same model as you get on.

Ready to update? Here's how to upgrade your iPhone or iPad to the new version of iOS