Apple has recently stopped signing iOS 17.6.1, meaning that users will no longer be able to downgrade after upgrading to iOS 18.
Apple recently released iOS 18 to the public, leading many users to upgrade to the newest OS to test the range of new features. However, this is a one-way trip as 9to5Mac reports that Apple has removed the IPSW files for iOS 17. IPSW, for those who don't recognize it, is the file format used to download an Apple OS to any device running Apple silicon. This means there is no way to downgrade to the older iOS after updating.
It is usually good practice to upgrade your phone as soon as possible, to benefit from the security changes included. However, iOS 17.7 currently contains the same security updates as iOS 18, meaning there is little reason to update other than to try out the new features.
It's worth adding that one Apple product can still downgrade, the M4 iPad Pro, due to a reported issue where the device is bricked by downloading iPadOS 18. Users who joined the iOS 18 beta can also still downgrade from the iOS 18.1 beta to iOS 18.0.
Some of the great features of iOS 18 might convince some people to upgrade, including expanded home screen customization.
The new update also comes with a new and improved control center, including new panels and customization options. Apple Photos has also seen a revamp, with a new layout and improved collections. However, the biggest sell will be Apple Intelligence once it actually leaves beta. Sadly the limitations on which devices can use Apple's new AI mean it won't be an automatic download for everyone.
One of the primary reasons users tend to downgrade is to avoid the slew of bugs that often accompany new OS versions. while iOS 18 has been relatively stable, there has been the odd issue. The most pressing is the recently discovered issue that causes the Messages app to repeatedly crash. This crash, which is a risk to data, occurs if a user shares an Apple Watch face to a message thread that is then replied to. The only known way to fix the bug is to delete the thread, but the constant crashing can still be an issue.
iOS 18 has plenty to offer, so not being able to downgrade likely won't be the biggest issue for many users. Plus if you've just picked up an iPhone 16, which is one of the best phones you can buy, you get to try all those features right out of the box.
