Once a year, at WWDC, Apple unveils its latest major update to the iOS software on iPads and iPhones, which will be launched to the public in autumn; it also launches small point updates to iOS throughout the year. But before each of these updates, it will be available for a limited time to the select few: the beta testers.

If you're desperate to try the newest iOS features as soon as possible, joining the beta programme is key. You'll get bragging rights among your friends, and if you're an app developer you can check that your apps work with the software changes.

There are two kinds of beta programme for iOS: developer previews (the earliest of all) and public betas, which come out slightly later but are still earlier than public releases. We explain how to join each, and how to install beta software, in this article.

Whether it's a good idea to join these programmes is another matter; we'll also talk about the pros and cons of installing beta software, and the reasons why you may prefer to wait a few months for the official public launch instead.

How to get the iOS Developer preview

Apple gets app developers to try out beta versions of iOS for a few months before it unleashes the final software on the public, and sicne the launch of iOS 9 it's also allowed the public try a beta. These betas are test versions - unfinished versions of iOS with pretty much all the features that will make it into the official build, but probably with a few cosmetic differences… not to mention some glitches and problems that will need to be fixed.

In other words, don't expect a perfect user experience. In particular, don't expect existing apps (ones that you may rely on, and which may worked great with the previous version of iOS) to work perfectly with the new version. A huge issue for beta users of iOS 8 was that WhatsApp was unusable, crashing upon opening.

But it could be worse than just a couple of apps not working right. Sometimes people find that certain models struggle to cope with a beta OS in any meaningful way, and you may find that your device is effectively bricked until the next beta comes out and fixes the problem. Experienced beta users always advise you to install a beta version of iOS on a secondary or spare device - an older (but still compatible) iPod touch rather than your main iPhone, say.

Anyway. If you know what you're getting into and still want to join the beta programme right now, you can register as an Apple developer and join the iOS Developer Program, which costs $99 a year.

Go to Apple's developer site and enrol using your Apple ID.

How to join the Public Beta

There is a public iOS beta programme for members of the public who are willing to install a pre-release testing version of the next iOS update on their devices, bugs and all, and provide feedback on any bugs and issues that need to be ironed out. Apple has experienced several issues with final public launches in the past, and the public beta programme is a bid to prevent that from happening again.

You can sign up to the programme by clicking Sign Up on the Apple Beta page and use your Apple ID.

We can't stress how important it is to back up your device before you download and install a beta version of iOS, or better still, use a secondary device that isn't your main iPhone or iPad to try the beta. Not only will that mean you won't lose everything if something goes wrong while the beta is installing, it also means you'll be able to go back to the last version should you find that you don't like the new software after all, or that it's too buggy.

We talk you through backing up your device in our how to back up an iPhone or iPad article.

Then, all you'll need to do is click Sign Up on the Apple Beta page and use your Apple ID.

You'll then be able to log in to the Beta Software Program, and click Enroll your iOS device. From there, you'll be instructed to go to beta.apple.com/profile on your iOS device in order to download and install a configuration profile. That will make the beta available in the Settings app, under General, Software Update.

How to install an iOS beta if you're a developer

Before downloading the beta, back up the device you're going to install the beta on. That way you can restore it fairly easily if something goes seriously wrong.

Sign into the iOS Dev Center using the Apple ID you used in the previous step.

Register your Apple device's UDID (the easiest way to find out your UDID is to plug the device into iTunes, click on the device's icon in the top right-hand corner, view the Summary tab and click on the Serial Number entry to get it to change to the UDID). Now you'll be able to download the appropriate version of the iOS beta for your hardware - select the exact iPhone, iPod touch or iPad model you're using from the list.

Unzip the file that downloads to your Mac (this should produce a .IPSW file). Connect your device to iTunes (if it isn't already).

Hold Alt (on a Mac - it's Shift on a PC) and click the Restore iPhone button on the device's Summary tab (next to Check for Update). Select the .IPSW file from the previous step. The iOS beta will be installed on your iPad or iPhone after a few minutes.

The down sides of installing an iOS update early

There are basically two down sides to grabbing a beta version of iOS early, but they're quite big.

  • Whereas downloading the new version of iOS when it's publicly available will be free, registering as an iOS developer costs $99 (but once you've done this, getting the beta is free - so this point doesn't apply to bona fide developers or anyone else who's already registered for other reasons). If you're installing the public beta, on the other hand, you won't have to pay.
  • The beta version will probably be buggy and may make your Apple device a nightmare to use, even if you opt for the free public beta.

On the other hand, getting the iOS beta will give you some serious bragging rights among your Apple-loving friends, and let you decide for yourself whether you like the new features and very broad design ideas. (Bear in mind that it'll be sharpened up a fair bit before the final launch.)

It will probably also be easier to get rid of the beta than the full version when it launches.

How to install the developer beta... if you're not a developer

The beta version you'll get on your device if you're using the public beta won't be the most up-to-date version that Developers have been testing. If you're desperate to have the latest build, there is another option available. Before we begin the how to, it's worth noting that once you update, none of the personal data accumulated on the firmware will be restorable if you later decide to downgrade again.

An easy way to get around this issue is to manually back up your device via iTunes before you upgrade, then exclusively use iCloud for backup once the upgrade is complete. This way, if you need to downgrade, you'll have a backup available - granted, it won't be the most up-to-date backup, but it's a better option than completely losing everything.

Step 1: Download the latest beta. These are usually released via the Apple Developers Portal, but you have to pay $99 a year to access this service (as discussed above). However there are also other sources that will supply users with the betas, with iMZDL being one of the most popular online resources.

There are many versions of the beta available, and it's important to download the corresponding beta for your device - if you download the wrong beta, iTunes will first wipe the old version of iOS 8 from your device before informing you that it's unable to install the selected iOS beta, which forces the device into DFU mode and requires a complete restore to fix. Some sites (iMZDL included) provide a service that uses your devices serial number to identify the correct beta to download.

Step 2: Download the latest version of iTunes. This is fairly straight forward - it's important to make sure that you're running the latest version of iTunes. You can download the latest version of iTunes via the Apple website, the App Store Updates tab on Mac or click Help > Check for Updates within iTunes for PC.

Step 3: Register your devices UDID. The UDID, or Unique Device Identifier, of your device has to be registered for developers use before installing the iOS beta. There are some reports that it isn't needed, but we think it's better to be safe rather than having to deal with UDID-related issues down the line.

You can either get an iOS developer friend to register your devices' UDID, or you can pay for it via iMZDL or ATFDL. If you're unsure of how to find the UDID of your device, you can follow our tutorial here.

Step 4: Back up your device. As mentioned earlier, we advise that you back up your device before installing the iOS beta because:

A) If anything goes wrong during the installation of the beta, you'll have a backup available - no harm done.

B) You won't be able to use any iOS 10 backups with iOS 9, for example, so if you downgrade with no backup, you'll have to completely wipe your iPhone.

This can be done by plugging your iPhone or iPad into iTunes, selecting the iPhone/iPad icon from the menu and then selecting 'Back Up Now'. It's also advised that you select 'iCloud' under the Backup menu as your automatic backup option as we don't want your backup being overwritten.

Step 5: Restore your device. Once you've followed the above steps and backed up your device, it's time to restore your iPhone to its factory settings. You can do this by clicking 'Restore iPhone/iPad' within iTunes with the device connected.

Though this step is advised by many publications online, we've installed the iOS beta on several of our devices without restoring our devices prior to the install and encountered no issues along the way.

Step 6: Install the beta. To install the iOS 9 beta on your device, make sure it's plugged in to your computer and select it within iTunes. Next, while holding the Option (Alt) key on Mac/Shift key on Mac, click the 'Check for Update' button.

This should open a window where you can browse for the iOS beta .IPSW file that you downloaded earlier. Navigate to wherever you chose to save the .IPSW file, select it and click open. iTunes may display a notification informing you that you're installing the new version of iOS - just click OK, then the installation process should initiate.

Step 7: Wait. The install process can take a while - the important thing is to not unplug/turn off your device during the install, as it may corrupt the operating system and 'brick' your device.

Step 8: Slide to upgrade. Once the upgrade process is complete and your device has restarted, you'll be prompted with a 'Slide to upgrade' screen. Swiping this will again reboot your iPhone, but don't panic - it's normal. Once it has rebooted, you'll be greeted with the familiar 'Hello' welcome screen. Follow the on-screen instructions and you'll be successfully running the iOS beta on your iPhone or iPad.