iOS 9.0 (build 13A344) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2015-09-16T18:02:16Z. The update package is 1011.79 MB. This is a delta (partial) update that requires 8.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f6446ecfb34225a098c2cfdee61e86b5facdd91a.zip.