Apple is no longer signing iOS 26.4 and iPadOS 26.4 for iPhone and iPad, which means downgrade from 26.4.1 is no longer possible.
You Can No Longer Downgrade from iOS 26.4.1 and iPadOS 26.4.1 to iOS 26.4 and iPadOS 26.4
You really don’t have to downgrade your iPhone or iPad to anything, given that every new iOS 26 and iPadOS 26 update adds new features and bug fixes along with security patches. Keeping your device up to date is the most logical thing to do.
If you’re currently on iOS 26.4 or iPadOS 26.4, I will suggest upgrading to the new 26.4.1 update immediately. All you have to do is go to Settings > General > Software Update on your device, and then tap on Update Now.
There are more software updates coming to iPhone and iPad. For example, Apple is currently working on iOS 26.5 and iPadOS 26.5, updates that should become available to everyone for download in a month’s time. Currently, both are available as developer and public betas.
