Download iOS 15.3.1 (19D52) for iPhone 6s+

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 iPhone8,2
iOS Version 15.3.1
Release Date 2022-02-10
Update Date 2022-02-07
Sha1sum
ec4163cc47dc688b58541c00f190f942e2db3101
Sha256sum
f0b9f27b497ebc88a29e0dc62a52bd92bdc6a7069808b450fa68fbbcd2523954
md5sum
fcfa141802a5bf1c95f5ebeaf21d4587
Size 5.21 GB
FileName
iPhone_5.5_15.3.1_19D52_Restore.ipsw
Status

Download IPSW (5.21GB) Check device info
Release Notes

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

iOS 15.3.1 provides important security updates for your iPhone and fixes an issue that may cause Braille displays to stop responding.

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

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