One of the smaller security features touted by Apple in the iOS 9 update was the move to requiring six-digit passcodes, rather than the default four-digit option that’s been around since the iPhone first debuted. While complex alphanumeric passwords have been available in iOS for years, most users found them to be too much trouble, so Apple reasoned that going from a four to a six-digit passcode was a more sensible compromise for improving security, particularly in an era of Touch ID devices, where the passcode rarely needs to be entered anyway.
The good news, however, is that while Apple encourages people to use a six-digit passcode by presenting it as the default option when setting up a new iOS device or even updating to iOS 9, you’re by no means limited to this option, and in fact iOS 9 now offers four different passcode/password configurations, rather than the four-digit code vs. password choice from prior versions. The option is a bit more hidden than it used to be, however; if you visit the Touch ID & Passcode section in the iOS Settings app, you’ll notice the former “Simple Passcode” option is nowhere to be found. Instead, a small blue link appears when you go to change your passcode, offering you the ability to switch to one of the other options: Custom Alphanumeric Code, Custom Numeric Code, 4-Digit Numeric Code, or 6-Digit Numeric Code (note that the current option isn’t shown here, as that’s what you’re already using).
Tapping on one of the options will change the passcode or password setting screen to use that format, so you can return to a four-digit passcode if that’s what you prefer, or if you want to get even more secure but don’t want to deal with a fully alphanumeric password, iOS 9 also offers the option of a “Custom Numeric Code” — you’ll get the numeric keypad instead of the full keyboard for passcode entry, but you can enter a string of numbers as long as you like.