How to Fix iTunes Error 1671 When Updating iPhone
What error 1671 means
Error 1671 is one of Apple’s iTunes update errors. It appears when you’re updating or restoring an iPhone through a computer: iTunes begins pulling the iOS software file (an IPSW file, often several gigabytes) from Apple’s servers, and partway through the download something goes wrong. iTunes then gives up and shows the 1671 dialog, and the update never starts installing.
The key detail is that 1671 is a download failure, not an installation failure. Your iPhone is completely untouched — all your photos, apps, and settings are exactly as they were. The frustrating part is that simply clicking the update button again often produces the same error, because iTunes tries to reuse the damaged partial file or hits the same interference each time.
The usual suspects are an unstable network connection (VPNs, proxies, and flaky Wi-Fi are repeat offenders), security software quietly blocking or quarantining the downloaded file, outdated iTunes or macOS misbehaving with Apple’s servers, or a partially downloaded file that got corrupted and keeps failing its integrity check. Work through the steps below in order — most 1671 cases resolve within the first few.
Common causes
- Interrupted download: the connection dropped or the computer slept mid-download, leaving a broken partial file.
- VPN or proxy interference: network tools reroute or inspect traffic in ways that corrupt large downloads.
- Outdated iTunes or macOS: old versions mishandle Apple’s current update servers.
- Security software blocking the file: antivirus or firewall flags the large downloaded file mid-transfer.
- Corrupted partial IPSW: iTunes keeps reusing a damaged file on every retry instead of fetching a fresh one.
How to fix error 1671 — step by step
Because 1671 is a download problem, start with the network and the download itself — that’s where the fault almost always lives.
- Stop and restart the download in iTunes. If iTunes is showing 1671 while fetching the update, quit iTunes completely, wait a minute, and reopen it. Plug the iPhone in with a certified cable, select it, and click Check for Update again. A fresh attempt often clears a transient download hiccup.
- Fix your network connection. Make sure the computer has a stable connection for a long, large download: disable any VPN or proxy (on Windows, go to Settings > Network & Internet > Proxy and turn it off), and if you’re on Wi-Fi, move closer to the router or switch to Ethernet. Also keep the computer awake — disable sleep temporarily so it can’t doze off mid-download.
- Update iTunes or macOS. On Windows with the Microsoft Store apps, open the Microsoft Store > Library and install updates for the Apple Music and Apple Devices apps (or in classic iTunes, go to Help > Check for Updates). On a Mac, open the Apple menu > System Settings > General > Software Update. Restart the computer after updating, then retry the update.
- Delete the partially downloaded update and retry. A corrupted partial download keeps failing the same way. Close iTunes, then delete the contents of
C:\Users\<you>\AppData\Roaming\Apple Computer\iTunes\iPhone Software Updateson Windows. On a Mac, open Finder, choose Go > Go to Folder, paste~/Library/iTunes/iPhone Software Updates, and delete the partial file. Reopen iTunes or Finder and start the update again — it will fetch a fresh, complete file. - Temporarily disable security software. Pause your antivirus and firewall: on Windows, go to Windows Security > Virus & threat protection > Manage settings, and temporarily turn off real-time protection and the firewall. Retry the update, then re-enable everything immediately afterward.
- Restart both devices — or update over the air instead. Restart the iPhone (Settings > General > Shut Down, then power back on) and restart the computer. If iTunes still throws 1671, sidestep it entirely: disconnect the iPhone and update over the air at Settings > General > Software Update. This downloads and installs the same iOS version without involving iTunes at all.
Did this fix it? Quick checklist
- No VPN, proxy, or unstable Wi-Fi between the computer and Apple’s servers
- iTunes (or macOS) fully updated and the computer restarted
- Partial IPSW download deleted so iTunes fetches a fresh file
- The update completes without 1671 — or the over-the-air update succeeds
If 1671 keeps appearing with a fresh download, current software, and security tools off, try a different network (a phone hotspot works for a test) to rule out your connection. Persistent failures across networks are rare — Apple Support can check whether your Apple ID region or device is hitting a server-side issue.
Frequently asked questions
What does iTunes error 1671 mean?
It means iTunes (or Finder) started downloading the iPhone software update but couldn’t finish the download — something interrupted or corrupted the transfer, so the update never began.
Will error 1671 erase anything on my iPhone?
No. Error 1671 happens before the update even starts installing, so your photos, apps, and data are untouched. The phone behaves exactly as it did before the attempt.
How long should I wait when the download stalls before doing anything?
Give it at least 30 minutes on a slow connection — big iOS files take a while. But if progress has been frozen for an hour or the 1671 dialog already appeared, don’t wait longer; restart the download using the steps above.
Why does error 1671 keep coming back on every update attempt?
Usually a corrupted partial download is being reused each time, or a security program keeps interfering. Deleting the partial IPSW file and temporarily disabling security software fixes the repeat-failure pattern.
Can I skip iTunes entirely and still update?
Yes — update over the air on the iPhone itself at Settings > General > Software Update. It delivers the same iOS version and avoids the iTunes download path completely, which is the simplest escape from a stubborn 1671.