Download iOS 11.3.1 (15E302) for iPhone 5s (GSM)

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

❌ This IPSW firmware is not being Signed by Apple

Firmware Identifier iPhone6,1
iOS Version 11.3.1
Release Date 2018-04-24
Update Date 2024-06-03
Sha1sum
dd1d1c8ff8afcd1d5f6f4cf30eb3d12a777beb3e
Sha256sum
64b892c580be1509e45e94a64be70e2e46b444b6cd48844dc7146a9af56ddc5a
md5sum
058d17d6c4486614cd760e76a0b66872
Size 2.53 GB
FileName
iPhone_4.0_64bit_11.3.1_15E302_Restore.ipsw
Status

Download IPSW (2.53GB) Check device info
Release Notes

It should be noted that these are the official release notes for the from Apple

iOS 11.3.1 improves the security of your iPhone or iPad and addresses an issue where touch input was unresponsive on some iPhone 8 devices because they were serviced with non-genuine replacement displays.

Note: Non-genuine replacement displays may have compromised visual quality and may fail to work correctly. Apple-certified screen repairs are performed by trusted experts who use genuine Apple parts. See support.apple.com for more information.

For information on the security content of Apple software updates, please visit this website:

https://support.apple.com/kb/HT201222