Starting with the release of iOS 9.0.1, Apple has increased your security by defaulting to 6-digit passcodes on Touch ID devices. “If you use Touch ID, it’s a change you’ll hardly notice,” says Apple.
Compared to 4-digit passcodes which have 10,000 possible combinations, their 6-digit counterparts strengthen your security with one million possible combinations, meaning 6-digit passcodes will be a lot tougher to crack.
Non-Touch ID iPhones and iPads still default to less secure 4-digit passcodes, however. You can enable a 6-digit passcode with a quick trip to Settings, here's how.