Erase iPhone Baseband Bootloader: Full Tutorial

This tutorial explains how to erase the baseband bootloader on an iPhone, a procedure used to reset the modem firmware to its factory state. This is typically done to fix boot loops, restore cellular functionality after a failed jailbreak, or prepare the device for a fresh baseband install. You will need a computer, a compatible iPhone, and the appropriate software tools. Proceed with caution: this process carries risk and may void warranties.

What You’ll Need

A Windows PC or Mac (Intel-based Mac recommended for compatibility)
A lightning or USB-C cable to connect your iPhone
The latest version of iTunes (or Finder on macOS Catalina or later)
The correct IPSW firmware file for your exact iPhone model and iOS version
Specialized tools: checkm8-based jailbreak (for compatible devices) and a baseband eraser tool (e.g., ipwndfu, gaster, or similar open-source utilities)
Backup of your iPhone data (this process will erase everything)
Stable internet connection for downloading firmware and tools

Step-by-Step

Back up your iPhone. Connect your iPhone to your computer, open iTunes/Finder, and select “Back Up Now.” Ensure the backup completes and verify its date/time.
Identify your iPhone model and iOS version. Go to Settings > General > About on your iPhone. Note the Model Number and the iOS version. You will need this to download the correct IPSW file.
Download the correct IPSW file. Visit a reliable IPSW download site (e.g., ipsw.me) and download the exact firmware for your device and iOS version. Save it to a known folder on your computer.
Download and set up the necessary tools. Download the checkm8-based jailbreak tool (e.g., checkra1n) and a baseband eraser utility (e.g., gaster or ipwndfu). Extract them to a folder. On Windows, you may need to install drivers (e.g., Apple Mobile Device Support).
Put your iPhone into DFU mode. Connect your iPhone to your computer. Turn off the iPhone. Hold the Power button for 3 seconds, then while holding Power, press and hold the Volume Down button for 10 seconds. Release the Power button but keep holding Volume Down for another 5 seconds. The screen should stay black; if the Apple logo appears, repeat.
Run the checkm8 exploit. Open a terminal/command prompt in the folder with your tools. Run the checkm8 tool (e.g., checkra1n or gaster) and follow its prompts to put the device in pwned DFU mode. You should see a success message.
Erase the baseband bootloader. With the device in pwned DFU mode, run the baseband eraser tool. For example, if using gaster, type gaster decrypt then gaster erase (exact commands vary by tool). This will wipe the baseband bootloader and its settings. Wait for the tool to confirm completion.
Restore the iPhone with the IPSW. Open iTunes/Finder. Your iPhone should appear in recovery mode. Hold Shift (Windows) or Option (Mac) and click “Restore.” Select the IPSW file you downloaded. iTunes/Finder will reinstall the firmware, which includes a fresh baseband bootloader.
Complete the setup. After the restore finishes, your iPhone will reboot. You can set it up as new or restore from your backup. Cellular functionality should work normally if the baseband was successfully erased and reinstalled.

Common Mistakes

Using the wrong IPSW. Downloading a firmware for a different iPhone model or iOS version will cause restore errors. Always double-check your device model and iOS version.
Incorrect DFU mode entry. Entering DFU mode incorrectly (e.g., holding buttons too long) can put the device in recovery mode instead. Practice until the screen stays completely black.
Not putting the device in pwned DFU mode. The baseband eraser requires the checkm8 exploit to be active. If you skip this step, the erase command will fail.
Interrupting the process. Unplugging the cable or closing the terminal during the erase can brick the baseband. Let every step finish completely.
Using incompatible tools. Some tools only support certain iPhone models or iOS versions. Verify compatibility before starting.

Tips

Work on a stable power source for your computer; a sudden shutdown can be disastrous.
Use a high-quality cable and connect directly to a USB port on your computer, not a hub.
Read the documentation for your specific tools—commands may differ slightly between versions.
If you are not comfortable with command-line tools, consider seeking help from experienced community members.
Keep a copy of the original IPSW in a safe place in case you need to restore again.

Troubleshooting

Erase command fails or hangs. Ensure your device is in pwned DFU mode. Re-run the checkm8 exploit and try again. If it still fails, try a different USB port or cable.

Restore gives error 9, 14, or 4013. These errors often indicate USB connectivity issues. Try a different cable, port, or computer. Also, make sure you have the correct IPSW.

iPhone stuck in recovery mode after erase. Use a tool like ReiBoot or re-run the restore process. If the device is recognized, simply restore again with the IPSW.

No cellular after restore. Check if the baseband version appears in Settings > General > About. If it says “Blank” or “1.00.00,” the baseband was not installed properly. Re-restore with a fresh IPSW.

Tool not recognized. On Windows, install the latest Apple Mobile Device USB driver. On Mac, ensure you have Xcode command line tools installed.

Device not entering DFU mode. Practice the button sequence. Some devices require precise timing. Try using a timer or watch a video tutorial.

Frequently Asked Questions

Is this safe for my iPhone? Erasing the baseband bootloader is a low-level operation. If performed correctly, it is safe, but any mistake can potentially brick the device. Always follow steps carefully.

Will this unlock my iPhone? No. Erasing the baseband bootloader does not unlock carrier restrictions. It only resets the modem firmware.

Does this work on all iPhone models? No. The checkm8 exploit works only on iPhone 5s through iPhone X (A7 to A11 chips). Newer models are not supported.

Can I do this without a jailbreak? The process requires checkm8, which is a hardware exploit, not a jailbreak. It works regardless of whether the device is jailbroken.

What if I don’t have the right IPSW? You must download the correct IPSW. Using a wrong one will cause restore errors. Use a trusted source like ipsw.me.

Will this erase all my data? Yes, the restore process wipes the entire device. Make a backup before starting.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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