What It Means to Downgrade iOS 26 → iOS 18

What It Means to Downgrade →

Downgrading means erasing your device and installing an earlier iOS firmware (in this case, iOS 18). Because Apple allows a limited window during which older versions are signed, you must act quickly if the window is still open.

If the version is no longer signed, you cannot perform the downgrade.

Prerequisites Before You Downgrade

Check signing status
Use a site like IPSW.me to see if iOS 18 (e.g. 18.6.2) is still signed for your specific iPhone model.
Backup your data
Use iCloud or Finder/iTunes to back up your device. Note: backups made while on iOS 26 usually cannot be restored to iOS 18.
Turn off Find My iPhone
Go to Settings → [Your Name] → Find My and disable it.
Download the correct iOS 18 IPSW file
Ensure the version matches your iPhone model (e.g. iPhone 12, 13, etc.).

How to Downgrade iOS 26 to iOS 18: Step-by-Step

1. Connect to Computer

Use a Lightning or USB-C cable to link your iPhone to a Mac or Windows PC.

2. Put Device into Recovery or DFU Mode

Follow the button sequence for your model to enable recovery mode — or better, DFU (Device Firmware Update) mode.

3. Initiate Restore with IPSW

On macOS (Finder): Hold Option key and click Restore iPhone
On Windows (iTunes): Hold Shift and click Restore iPhone
Then select your iOS 18 IPSW file.

4. Wait for Downgrade Process

Your device will reboot several times during the restoration. Don’t disconnect it.

5. Set Up Device

Once completed, set it up as new or attempt to restore a backup made earlier (ideally from iOS 18).

Tips, Risks & Alternatives

Tip / Risk	Details
Data loss risk	Downgrade wipes your device. You cannot restore a backup made under iOS 26 to iOS 18.
Signing window can close anytime	Apple may stop signing older iOS versions unexpectedly.
Use trusted tools	Third-party tools like Tenorshare ReiBoot claim safer downgrade procedures with fewer complications.
Only downgrade if necessary	iOS 26 offers new features and updated security, although users have flagged performance lags.

Summary

In 2025, knowing how to downgrade iOS 26 to iOS 18 can save you from bugs or performance issues — but only if Apple still signs the older version. Back up your device, turn off Find My iPhone, get the correct IPSW, and perform a restore via Finder or iTunes.

If you discover iOS 18 is no longer signed, the downgrade will fail — you may have to stick with iOS 26 or wait until Apple stops signing newer versions.