Here’s a iOS 11.3.1 IPSW download link for iPhone, iPad or iPod touch. With iOS 11.3.1 ipsw download, you can restore or update your iPhone/iPad manually via iTunes.
Apple surprisingly releases the new iOS 11.3.1 for iPhone/iPad to fix an Indian character crashing bug on iPhone when sending and Indian character through messages or messenger. Along with that, it fixes an issue where some third party apps could fail to connect to external accessories.
iOS 11.3.1 has no new features rather than the bug fix. You can download and update iiOS 11.3.1 right from your iPhone/iPad via OTA software update settings>> general>>software update or through iTunes.
You can also update your iPhone/iPad to iOS 11.3.1 using iTunes. It will auto detect your device when connected your iOS device to iTunes via lightning USB cable, and pops up a notification to download the update. You can go through it and let install iOS 11.3.1 automatically.
For some how if you have network connectivity issue while downloading the iOS 11.3.1 via iTunes, then you need to update your iPhone/iPad manually with IPSW file below.