iOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2015-06-30T15:51:22Z. The update package is 1.34 GB. This is a delta (partial) update that requires null already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 84e39c30d612b0a58aec597bf7ac8e85af873034.zip.