Error 4013 on iPhone: Causes and 5 Proven Fix Methods

What Does Error 4013 Mean

Error 4013 is a rejection code that appears when attempting to update or restore the iOS operating system on an iPhone or iPad via iTunes (on Windows computers) or Finder (on a Mac). In the dialog box, you will see the message: "Could not update iPhone. An unknown error occurred (4013)."

This error typically indicates a communication problem between the device and the computer or firmware corruption. It blocks the update/restore process but does not cause the device to "freeze"—the iPhone remains in recovery mode and can be rebooted.

Error 4013 most commonly occurs during:

• iOS updates via iTunes/Finder.
• Restoring the device to factory settings.
• Attempting to downgrade to an older version of iOS.

Causes

Error 4013 is not random—it is based on a specific failure. Here are the main causes, sorted from most to least probable:

1. Faulty USB Connection
   • Using a non-original or damaged Lightning/USB-C cable.
   • A problematic USB port on the computer (dust, physical damage).
   • Connecting via a USB hub or extension cable that does not provide stable data transmission.
2. Insufficient Free Space on iPhone/iPad
   • Updating iOS requires temporary space (up to 5 GB). If the device has little storage, the process is interrupted with error 4013.
3. Outdated Software
   • iTunes on Windows or macOS on the Mac is not updated to the latest version.
   • An old version of iOS drivers is installed on the computer (particularly relevant for Windows).
4. Temporary Apple Server Outage
   • A connection disruption can occur while downloading the firmware from Apple's servers, leading to error 4013.
5. Corrupted iOS System Files
   • The device already has critical OS corruption that prevents the update/restore process from completing correctly.
6. Conflict with Security Software
   • Antivirus, firewalls, or system optimization software on the computer may block the iTunes/Finder connection to the iPhone.
7. Authorization Issues
   • The "Trust This Computer?" option was not enabled on the iPhone upon first connection.
   • Outdated or incorrect Apple ID credentials in iTunes.

Solutions

We have compiled proven methods, from simple and quick to more complex. Start with the first method and proceed sequentially.

Method 1: Check Hardware Connection and Force Restart

Most often, error 4013 is caused by an unstable physical connection. This method resolves the issue in about 40% of cases.

1. Disconnect the iPhone from the computer.
2. Restart both devices:
   • On the iPhone: Press and hold the power button and one of the volume buttons (on models without Face ID) or the power button and one of the volume buttons (on models with Face ID) until the slider appears. Drag it to power off, then turn it back on.
   • On the computer: Fully shut down and wait 30 seconds before turning it back on.
3. Connect the iPhone directly to a USB port on the back panel of the computer (if it's a desktop PC), avoiding hubs and front-facing ports.
4. Use an original or Apple-certified cable. If possible, try a different cable.
5. Launch iTunes/Finder and repeat the update/restore.

⚠️ Important: If a dialog appears on the iPhone asking "Trust This Computer?"—be sure to tap "Trust" and enter the device passcode.

Method 2: Update Software and Free Up Space

Compatibility issues or lack of space are the second most common cause.

1. Update iTunes (Windows) or macOS (Mac):
   • Windows: Open iTunes → Help menu → Check for Updates. Install the latest version.
   • Mac: Open System Settings → Software Update. Install all available macOS updates.
2. Free up space on the iPhone:
   • Go to Settings → General → iPhone Storage → Review Large Attachments or similar.
   • Delete unnecessary apps, old videos, or photos (they can be saved to iCloud or a computer).
   • Updating iOS requires a minimum of 4–5 GB of free space.
3. Reconnect the device and repeat the operation.

Method 3: Disable Antivirus and Firewall

Security software can unintentionally block the iTunes/Finder connection to the device.

1. Temporarily disable the antivirus and firewall on the computer (e.g., Windows Defender, McAfee, Kaspersky).
2. Disable VPN clients and proxy services if they are active.
3. Repeat the update/restore.
4. After successful completion, re-enable the protection.

Method 4: Restore in DFU Mode (Full)

If the previous methods did not help, the iOS system layout is likely corrupted. DFU (Device Firmware Update) mode boots the device into a state that allows the firmware to be re-flashed from scratch.

Attention: This method erases all data on the iPhone. Ensure you have a current backup in iCloud or on your computer.

How to Enter DFU Mode:

For iPhone 8, SE (2nd generation), and newer:

1. Connect the iPhone to the computer.
2. Quickly press and release the volume up button.
3. Quickly press and release the volume down button.
4. Press and hold the power button until the screen goes black (about 10 seconds).
5. While continuing to hold the power button, press and hold the volume down button for another 5 seconds.
6. Release the power button, but continue holding the volume down button for 15 seconds.
7. If the screen remains black and iTunes/Finder shows the device in recovery mode—DFU mode is active.

For iPhone 7 and 7 Plus:

1. Connect the device to the computer.
2. Press and hold both the volume up button and the power button simultaneously.
3. After 8 seconds, release the power button, but continue holding the volume up button for 5 more seconds.
4. If the screen is black and iTunes/Finder detects the device in recovery mode—DFU is active.

For iPhone 6s, SE (1st generation), and earlier:

1. Connect the iPhone to the computer.
2. Press and hold both the home button and the power button simultaneously.
3. After 10 seconds, release the power button, but continue holding the home button for 5 seconds.
4. If the screen remains black and iTunes/Finder shows the device in recovery mode—DFU mode is active.

After Entering DFU:

1. iTunes/Finder will display a message that an iPhone in recovery mode has been detected.
2. Click "Restore iPhone" (or "Restore iPhone").
3. iTunes/Finder will download the latest iOS version and install it on the device.
4. After completion, set up the iPhone as new or restore from a backup.

Method 5: Contact Apple Support

If none of the methods helped, the problem may be hardware-related:

• A damaged Lightning/USB-C port on the iPhone.
• Power or memory controller failures.
• Issues with the motherboard.

In this case:

1. Bookmark an appointment at an Apple Store or an authorized service center via the Apple website or the "Apple Support" app.
2. Explain the situation: error 4013 persists even after DFU restore attempts.
3. If the device is under warranty—the repair will be free.

Prevention

To avoid encountering error 4013 again in the future, follow these recommendations:

• Use only original or Apple-certified cables (with the MFi logo). Cheap alternatives often cause connection failures.
• Update iTunes/Finder and macOS immediately after updates are released. Enable automatic updates.
• Free space: Regularly ensure your iPhone has at least 6–8 GB of free storage for updates.
• Do not interrupt the update/restore process—do not unplug the cable, turn off the computer, or power down the iPhone.
• Back up your data via iCloud or computer before any firmware manipulations.
• Disable antivirus during iOS updates if you have previously experienced connection errors.
• Use direct USB ports on the computer, avoiding hubs and front-panel ports on desktop cases, which may have insufficient power.