How can I revert iphone to previous ios 18?

Unfortunately, Apple does not officially support downgrading iOS once you've upgraded to a newer version, and revert back to iOS 18 from 26 or iOS 19 is generally not possible through official methods once Apple stops signing the older version. This process can be tricky and often results in data loss, so it’s important to consider the risks.

Here's what you need to know:Apple's Signing Window: Apple only signs older versions of iOS for a limited period after a new version is released. Once a new iOS version is rolled out (e.g., iOS 26), Apple typically stops signing the previous versions (e.g., iOS 18 and iOS 19). This means that unless Apple is still signing iOS 18 or 19, you won’t be able to officially revert back to iOS 18 from 26.

Is It Safe to Downgrade?No — even if you could downgrade, there's a high chance of data loss or issues when attempting to revert to a previous iOS version. Apple typically recommends staying on the latest iOS for stability and security.

Can I Downgrade Using iTunes?No — iTunes or Finder (on Mac) does not officially allow downgrading iOS to a previous version unless Apple is still signing that version.

Data Loss Risk: If you manage to find an unofficial method (through third-party tools), there's a high risk of losing data. So, it’s crucial to have a backup before attempting anything.