Download iOS 13.3 (17C54) 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 iPhone8,1
iOS Version 13.3
Release Date 2019-12-10
Update Date 2019-12-05
Sha1sum
66e423869cfe69ced386d3eccea595caa42ff86f
Sha256sum
dad0fe7c5f93bce41d09e5c5b172cec80912afddf254b17efe549d17c53c096b
md5sum
978e3687e0f3f72fbba19e5ad3f74723
Size 3.46 GB
FileName
iPhone_4.7_13.3_17C54_Restore.ipsw
Status

Download IPSW (3.46GB) Check device info
Release Notes

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

iOS 13.3 includes improvements, bug fixes and additional parental controls for Screen Time.

Screen Time

Apple News

Stocks

This update also includes bug fixes and other improvements. This update:

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

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