September 25, 2025, 6:33 am | Read time: 2 minutes
iOS 26 has been available since mid-September, and Apple is increasingly urging hesitant users to update. However, this decision should be carefully considered, as it is no longer possible to downgrade to an earlier iOS version.
Brand-new updates can often lead to problems—especially when they introduce not only new features but also a completely new look, like iOS 26. Users are reporting on social media about shorter battery life, Bluetooth issues, and overheating. Until a few days ago, affected users could still revert to iOS 18. That is no longer possible, as Apple has stopped signing iOS 18.6.2 for all models that also support iOS 26.
Why Must an iOS Version Be “Signed”?
The process of downgrading to an older iOS version is not straightforward. Unlike over-the-air updates (OTA), which install automatically, it requires an IPSW archive file. While this can be downloaded in a browser, installation only works via iTunes for Windows or the Finder in macOS.
The issue: Apple’s update servers only accept the installation of signed iOS versions. This ensures that older—and potentially insecure—versions are no longer circulated. Without the signature, the archive file cannot be installed on the iPhone.
No More Downgrades After Updating to iOS 26
In the current situation, Apple has stopped signing iOS 18.6.2, as reported by sources such as “MacRumors.” Currently, only iOS 18.7 and iOS 26 are available as signed versions. However, the corresponding IPSW file for iOS 18.7 is only available for iPhone XS, XS, and XR, which cannot update to iOS 26 anyway. For all newer models, Apple only signs iOS 26.
Those who have not yet updated to the latest iOS version can still install iOS 18.7 and thus delay the transition. The latest iOS 18 version offers the same level of security as iOS 26 but potentially causes fewer problems. Upcoming updates like iOS 26.1 are also likely to be accompanied by security patches in the form of 18.7.1, etc. Hesitant users still have some time.