Apple released iOS 11.3.1 to fix an issue where touch input was unresponsive on some iPhone 8 devices because they were serviced with non-genuine replacement displays
According to iOS 11.3.1 release notes, iOS 11.3.1 also improves the security of the iPhone and iPad.
You can install the iOS 11.3.1 update wirelessly, but if you’re not getting the OTA update then you can find the direct links to download iOS 11.3.1 firmware (IPSW) files for iPhone, iPad and iPod touch so that you can update it manually using iTunes. If you are interested in jailbreaking then the golden rule is stay where you are and avoid updating to the latest version to improve your chances of jailbreaking your iPhone, iPad or iPod touch.
Download iOS 11.3.1 for iPhone:
iOS 11.3.1 (iPhone 5s GSM): iPhone_4.0_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 5s GSM+CDMA): iPhone_4.0_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 6 Plus): iPhone_5.5_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 6): iPhone_4.7_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 6s): iPhone_4.7_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 6s Plus): iPhone_5.5_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone SE): iPhone_4.0_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 7 GSM+CDMA): iPhone_4.7_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 7 Plus GSM+CDMA): iPhone_5.5_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 7 GSM): iPhone_4.7_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 7 Plus GSM): iPhone_5.5_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 8 GSM+CDMA): iPhone_4.7_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 8 Plus GSM+CDMA): iPhone_5.5_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 8 GSM): iPhone_4.7_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone 8 Plus GSM): iPhone_5.5_P3_11.0_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone X GSM+CDMA): iPhone10,3,iPhone10,6_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPhone X GSM): iPhone10,3,iPhone10,6_11.3.1_15E302_Restore.ipsw
Download iOS 11.3.1 for iPad:
iOS 11.3.1 (iPad Air Wi-Fi): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Air Cellular): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 2 Wi-Fi): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 2 Cellular): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Air China): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 2 China): iPad_64bit_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 3 Wi-Fi): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 3 Cellular): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 3 China): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Air 2 Wi-Fi): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Air 2 Cellular): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 4 Wi-Fi): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Mini 4 Cellular): iPad_64bit_TouchID_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro Wi-Fi): iPadPro_12.9_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro Cellular): iPadPro_12.9_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 9.7 Wi-Fi): iPadPro_9.7_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 9.7 Cellular): iPadPro_9.7_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad 5 Wi-Fi): iPad_64bit_TouchID_ASTC_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad 5 Cellular): iPad_64bit_TouchID_ASTC_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 12.9 Wi-Fi 2nd Gen): iPad_Pro_HFR_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 12.9 Cellular 2nd Gen): iPad_Pro_HFR_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 10.5 Wi-Fi): iPad_Pro_HFR_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad Pro 10.5 Cellular): iPad_Pro_HFR_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad 6 Wi-Fi): iPad_64bit_TouchID_ASTC_11.3.1_15E302_Restore.ipsw
iOS 11.3.1 (iPad 6 Cellular): iPad_64bit_TouchID_ASTC_11.3.1_15E302_Restore.ipsw
Download iOS 11.3.1 for iPod Touch:
iOS 11.3.1 (iPod touch 6G): iPodtouch_11.3.1_15E302_Restore.ipsw
If you need help on how to install iOS 11.3.1 on your iPhone, iPad or iPod touch then you can check our post for the step-by-step guide.
Let us know it goes, and which bugs were fixed after installing the iOS 11.3.1 update.