iOS 7.1 (build 11D169) is an official Apple over-the-air update for the iPhone 4 (GSM / 2012), released on 2014-03-10T16:59:00Z. The update package is 151.95 MB. This is a delta (partial) update that requires 7.0.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c55e72ef8f59176debdd1dcfd2063e3dbba39ab7.zip.