Many enthusiasts choose to "skachat" (download) iOS 6.1.3. This is widely considered the best firmware for the 4S because of its skeuomorphic design and lightning-fast speed.

For most users, the journey ends at . This was a special maintenance release issued years after the 4S was discontinued to fix a GPS rollover bug. Performance: It is heavy for the A5 chip.

If you are looking to push the limits, the jailbreak community offers tools to modify your firmware. The primary jailbreak for iOS 9.3.6.

Ideal for using the phone as a dedicated music player (iPod) or a retro gaming device. Where to Download (Skachat) Firmware

Red entries are "Unsigned" (requires special tools like Legacy-iOS-Kit). 2. Custom Firmware & Jailbreaking

The iPhone 4S is a "forever phone" in the eyes of the modding community. Whether you stay on the modern-ish iOS 9.3.6 or retreat to the nostalgic speed of iOS 6.1.3, the firmware you choose defines the soul of the device.

Very limited; most modern apps require iOS 12 or higher. Stability: High, but the interface can feel sluggish. The "Sweet Spot": iOS 6.1.3

Learn the button combination (Power + Home) to put the device into Device Firmware Update mode if it gets stuck.