iOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPhone 4s, released on 2015-06-30T15:51:17Z. The update package is 370.1 MB. This is a delta (partial) update that requires 8.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ab7eed0b7a84d5d27913efacaaf404c685da2075.zip.