In the spring of 2017, Apple released iOS 10.3.1, a minor maintenance update — and for a slice of iPhone owners, it was the update that made their phone feel a step slower. Forums filled with people asking how to go back to iOS 10.3, which had felt snappier on their devices. Rolling back was possible, but only under one strict condition: Apple had to still be signing the older firmware. Here is how the downgrade process worked, step by step.
A quick note before we start: this is a historical guide. Apple’s signing window for iOS 10.3 closed years ago, so these exact steps no longer work for that version — but the process shows how iOS downgrades have always functioned, and the backup discipline it teaches still applies today. If update reminders are driving you up the wall in the meantime, see our guide on completely blocking iOS update prompts on iPhone.
Step 1: Check that Apple still signs the older firmware
Apple cryptographically signs every iOS version it allows to be installed. The moment it stops signing a version, no iPhone can be restored to it — iTunes simply refuses. So the first step was always to confirm iOS 10.3 was still being signed. The community site ipsw.me tracks signing status in real time, and MacRumors and 9to5Mac reported each signing closure as it happened.
Step 2: Back up your iPhone
A restore wipes the phone, so a current backup was non-negotiable. Owners made an encrypted backup to their computer — encrypted backups also preserve passwords and Health data — or backed up to iCloud. One catch: a backup made on iOS 10.3.1 could not be restored onto iOS 10.3, so anything created after the update would be lost in the rollback. For keeping data flowing between devices afterward, our walkthrough for setting up message sync between iPhone and Mac is worth a read.
Step 3: Download the iOS 10.3 firmware file for your exact model
On ipsw.me, you picked your device — iPhone 7, iPhone 6s, and so on — because the model had to match precisely, and downloaded the iOS 10.3 IPSW file. These files are large, often over two gigabytes, so a stable connection mattered, and renaming the file afterward was asking for trouble.
Step 4: Restore through iTunes with the downloaded firmware
With the iPhone connected to the computer and iTunes open, you selected the device, then held the Option key on a Mac (or the Shift key on Windows) and clicked Restore iPhone. A file picker appeared — you chose the iOS 10.3 IPSW and confirmed. iTunes verified the file against Apple’s servers, which is where the signing check happened, and installed it. Apple’s own guide to restoring an iPhone covers the standard flow this process built on.
Step 5: Silence the update reminders
Once back on iOS 10.3, the phone would promptly start nagging to reinstall 10.3.1. Owners who wanted to stay put blocked the nagging with configuration profiles or by declining the prompt each time — our modern equivalent guide explains how to stop iOS update reminders entirely.
If it still doesn’t work
The most common failure was discovering mid-process that Apple had already closed the signing window: iTunes threw an error and refused the restore, leaving the phone on 10.3.1. There was no workaround — the window typically stayed open only days or weeks after a release. A mismatched IPSW for the wrong iPhone model failed verification too, so double-checking the download was essential.
Frequently asked questions
Can I still downgrade to iOS 10.3 today?
No. Apple stopped signing iOS 10.3 back in 2017, and once a signing window closes it never reopens. This guide survives as a historical record of how the process worked.
Did downgrading delete everything on the phone?
Yes — a firmware restore erases the device, which is why the backup step mattered so much. Only data backed up before the downgrade could be brought back.
Conclusion
Downgrading from iOS 10.3.1 to iOS 10.3 was a race against Apple’s signing window: confirm signing was live, back up, download the exact IPSW from a trusted source like ipsw.me, and restore through iTunes with Option or Shift held down. The window is long closed, but the lesson endures — back up before every update, because you may not get a second chance to go back.
