iOS 8.3 (build 12F70) is an official Apple over-the-air update for the iPhone 6, released on 2015-04-08T17:56:17Z. The update package is 285.5 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c76546103ce865be18d029c8db290830f5caa8b7.zip.