A1431
![iPhone 4[S] (iPhone4,1) - Front view](/images/devices/iPhone4,1.png)
- Earliest Firmware
- iOS 5.0
- October 7, 2011
- Latest Firmware
- iOS 9.3.6
- July 22, 2019
- Total Firmware
- 44 releases
- Support Span
- 7 years 9 months
The model number A1431 belongs to the iPhone 4[S] (device identifier iPhone4,1). Apple assigns multiple model numbers to each device for regional and connectivity variants, so one device usually carries several of them.
How do I find the model number on my device?
Open Settings > General > About and read the Model Number field. The number is also printed in the fine print on the back of the device and, on some models, on the SIM tray. Our model identification guide walks through every method.
What is the difference between A1387 and A1431?
Nothing software-related. These model numbers all refer to the same iPhone 4[S]; Apple uses them for regional and connectivity variants, and firmware support is identical across all of them.