- Phones and tablets
- iPhone
Error 4013
Apple error 4013 on iPhone or iPad: connection lost during update or restore
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
The computer lost its connection with the iPhone or iPad during the update or restore. Update your Mac, the Apple Devices app or iTunes, force restart the device and click Update, not Restore.
Safety first
Stop and check this first
- Restore reinstalls iOS and erases all your data. Always choose Update first and avoid restoring without a recent backup when you can.
Safe checks you can perform
- Mac, Apple Devices app or iTunes up to date
- Force restart and choose Update instead of Restore
- USB cable, port and computer
- Third-party security software
Leave these tasks to a qualified professional
- Do not attempt this professional task: Contact Apple Support
- Do not attempt this professional task: Diagnosis at Apple or an Apple Authorized Service Provider
What a technician must be able to justify
A technician is coming
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Contact Apple Support
What they doIf the error repeats after updating the computer, changing the cable and trying another computer, Apple Support reviews the case and decides whether service is needed.
They must show youthe case number and the steps they asked you to repeat.
In writingthe diagnosis and, if there is a repair, the part and the reason.
Diagnosis at Apple or an Apple Authorized Service Provider
What they doAn Apple or Apple Authorized Service Provider technician checks the device with their diagnostic tools and repeats the restore on their own computer and network.
They must show youthe device test result and that the restore also fails on their equipment.
In writingwhich test failed, which part is replaced, its reference and the reason.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Checks and evidence, step by step
Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
- 1
Mac, Apple Devices app or iTunes up to date
No special tools
Procedure
- Who:
- you.
- How:
- on a Mac install any pending macOS updates; on a Windows PC update the Apple Devices app or iTunes. If the computer restarts to update, check for updates again afterwards.
- Result that matters:
- the computer has no pending updates before you try again.
- If the error goes away on the next try:
- the computer software was out of date and the most likely cause.
- If the error returns with everything up to date:
- rule out the computer software and move to the next check.
- Evidence to keep:
- the macOS, Apple Devices or iTunes version and a photo of the message with the error number.
Evidence: iOS update and restore errors · If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
- 2
Force restart and choose Update instead of Restore
No special tools
Procedure
- Who:
- you.
- How:
- force restart the device (iPhone 8 or later: press and quickly release Volume Up, press and quickly release Volume Down, then hold the side button until the Apple logo appears). Connect it with a USB cable, locate it on the computer and, when offered, click Update, not Restore.
- Result that matters:
- whether the update finishes and the device starts with your data.
- If it finishes:
- the drop was a one-off; Update reinstalls the software and keeps your personal data.
- If the device starts in recovery mode:
- Apple says to restore it instead of updating, then set it up from a backup.
- Evidence to keep:
- which option you chose and the final message on the computer.
Evidence: If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
- 3
USB cable, port and computer
No special tools
Procedure
- Who:
- you.
- How:
- use the cable that came with the device or another Apple-certified USB cable; switch to a different USB port on the computer, never the keyboard port (Apple warns keyboards often lack sufficient power), and if it still fails try another computer. Try again after each change.
- Result that matters:
- which combination of cable, port and computer makes the error go away.
- If it goes away after changing the cable or port:
- the USB connection was the cause; stop using that cable or port for restores.
- If it repeats with another cable and another computer:
- rule out the USB connection and check security software.
- Evidence to keep:
- which cable, port and computer you tried and the result of each attempt.
Evidence: iOS update and restore errors · If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
- 4
Third-party security software
No special tools
Procedure
- Who:
- you, on your own computer.
- How:
- check whether an antivirus, firewall or other non-Apple security software blocks connections during the update. Set it up to allow them or turn it off temporarily following its maker's instructions, then try again.
- Result that matters:
- whether the error changes or goes away with protection adjusted or paused.
- If it works then:
- the security software was blocking the connection; keep a rule that allows the update and turn protection back on.
- If nothing changes:
- turn protection back on; the cause is elsewhere.
- Evidence to keep:
- the security software name and the setting you changed.
Evidence: iOS update and restore errors
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Phones and tablets
- Brand
- Apple
- Product type
- iPhone
Known code variants
- 4013
- An unknown error occurred (4013)
- error 4013
- iPhone error 4013
- Se ha producido un error desconocido (4013)
What it means
Apple shows "An unknown error occurred (4013)" when the device disconnects during the update or the computer loses its connection with it during the restore. Apple's general list groups this number with USB connection faults. It can come from the USB cable or port, out-of-date computer software or security software cutting the connection. The number does not identify a failed part.
Warnings and stop conditions
- Highsource verified
Restore reinstalls iOS and erases all your data. Always choose Update first and avoid restoring without a recent backup when you can.
Evidence: If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch · If you can't update or restore your iPhone or iPod touch
Symptoms and causes
Probable causes · in order
- USB connection dropCommon
The error shows up on one computer and cable and goes away after changing the cable, port or computer.
Evidence: iOS update and restore errors · If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
- Out-of-date computer softwarePossible
It goes away after installing macOS, Apple Devices or iTunes updates, without touching the cable.
Evidence: If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
- Security software interrupting the connectionPossible
It persists with another cable but changes when the computer's antivirus or firewall is adjusted or paused.
Evidence: iOS update and restore errors
Virtual technician
Does Error 4013 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Apple · 2026 · official_doc
- 2
If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch
Apple · 2026 · official_doc
- 3
If you can't update or restore your iPhone or iPod touch
Apple · 2026 · official_doc
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