Downgrading an iPhone 4s to iOS 5 is one of the most popular projects for vintage tech enthusiasts because it restores the device's original lightning-fast performance and the iconic "skeuomorphic" design of the early Steve Jobs era.
A computer running Linux or macOS is highly recommended for the most reliable tools like Legacy iOS Kit . downgrade iphone 4s to ios 5
The official iOS 5.1.1 IPSW for the iPhone 4s, which you can download from sites like IPSW.me . Method 1: Legacy iOS Kit (Recommended) Downgrading an iPhone 4s to iOS 5 is