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Technical Guide to Jailbreaking a Nintendo 3DS with MSET9

Guide version MIT License

Updated on May 24, 2026. This procedure explains how to install boot9strap and Luma3DS on a Nintendo 3DS/2DS family console using MSET9 only.

Legal note: this guide is intended for homebrew, personal backups, preservation, and maintenance of your own console. It does not cover downloading, installing, or distributing pirated software.

Introduction to MSET9

MSET9 is the exploit currently used by the Nintendo Homebrew guide for recent firmware versions, including 11.17.0-50E on European consoles. It works on Old 3DS/2DS and New 3DS/2DS models when the correct console model and firmware version are selected.

Technically, MSET9 exploits a vulnerability related to how the console handles data inside the Nintendo 3DS folder on the SD card. The procedure temporarily manipulates the data profile and the ID1 folder name, then uses a controlled sequence involving Mii Maker and Data Management to launch SafeB9SInstaller.

The final result is:

  1. boot9strap installed as a permanent loader;
  2. Luma3DS booting through boot.firm;
  3. essential homebrew tools installed through the finalize package.

Table of Contents

Downloads and Resources

Prefer the official links below. Avoid repacked bundles from videos, random mirrors, or archives that cannot be verified.

PC Preparation (Base Injection)

Requirements

  • The console SD or microSD card, readable from a PC.
  • The latest MSET9 archive, downloaded from the official MSET9 release.
  • Python 3.x installed on your computer.
  • A console that is updated or whose firmware version has been checked in System Settings; the version appears in the lower-right corner of the upper screen, for example Ver. 11.17.0-50E.

Copying Files to the SD Card

  1. Power off the 3DS completely.
  2. Remove the SD card from the console and insert it into the PC.
  3. Open the MSET9.zip archive.
  4. Extract all contents to the root of the SD card.
  5. If Windows, macOS, or Linux asks whether to overwrite existing files, confirm the overwrite.

The root of the SD card is the top level of the card, the same level where the Nintendo 3DS folder is normally located.

Launching the MSET9 Script

Run the script from the SD card:

  • Windows: launch MSET9-Windows.bat or, in older packages, mset9.bat.
  • macOS: launch MSET9-macOS.command or run python3 mset9.py from the root of the SD card in Terminal.
  • Linux: open a terminal in the root of the SD card and run python3 mset9.py.

If the script does not start correctly on Windows, install Python from python.org instead of relying only on the Microsoft Store version.

Selecting the Console Model and Firmware

In the MSET9 command-line menu:

  1. select the number matching your exact console model:
    • Old 3DS / Old 3DS XL / Old 2DS;
    • New 3DS / New 3DS XL / New 2DS XL.
  2. select the exact firmware version, for example 11.17.0-50E, 11.17.0-50U, or the regional variant shown by the console;
  3. verify that the script shows the correct model and version;
  4. choose option 1 to create the initial MSET9 ID1;
  5. when prompted, confirm the disclaimer by typing 1 again;
  6. wait for the Created hacked ID1. message;
  7. close the script by pressing Enter.

After this stage, the HOME Menu may look empty or may not show installed software. This is normal: user data is temporarily hidden and will be restored after removing MSET9.

Console Preparation

Generating the Required Data

  1. Reinsert the SD card into the 3DS.
  2. Power on the console.
  3. Open Mii Maker.
  4. Wait for the Mii Maker start screen or the normal application menu.
  5. Exit Mii Maker and return to the HOME Menu.
  6. Open System Settings.
  7. Go to Data Management > Nintendo 3DS > Software.
  8. If a software database reset or initialization prompt appears, confirm it. This does not delete your personal data.
  9. Exit System Settings.
  10. Power off the console completely.

This sequence generates and initializes the system data required by MSET9, including data linked to Mii Maker and SD card content management.

Checking MSET9 Status

  1. Remove the SD card from the console and reconnect it to the PC.
  2. Launch the script again:
    • Windows: MSET9-Windows.bat or mset9.bat;
    • macOS/Linux: python3 mset9.py from the root of the SD card.
  3. Select the correct model and firmware again.
  4. Check that the displayed status is Ready.

If the script shows Not ready, use the status check option, usually 2, and fix any missing items before continuing.

Triggering and Installation (SafeB9SInstaller)

Injecting the Exploit

This is the most delicate part of the process: do not press extra buttons and do not touch the screen when the guide tells you not to.

  1. Reinsert the SD card into the 3DS.
  2. Power on the console and make sure the System Settings icon is selected on the HOME Menu.
  3. Open System Settings with A.
  4. Go to Data Management > Nintendo 3DS > Extra Data.
  5. Stop on this screen. Do not press any other buttons and do not touch the screen.
  6. With the console still powered on and still on Extra Data, remove the SD card.

Note about removing the SD card while the console is on: removing the SD card while the 3DS is powered on is normally discouraged. In this specific screen, however, it is an intended, safe, and required operation for triggering MSET9 correctly.

  1. Connect the SD card to the PC.
  2. Launch the MSET9 script again:
    • Windows: MSET9-Windows.bat or mset9.bat;
    • macOS/Linux: python3 mset9.py from the root of the SD card.
  3. Select the correct model and firmware.
  4. Choose option 3 to inject MSET9.
  5. Wait for the MSET9 successfully injected! message.
  6. Close the script by pressing Enter.
  7. Safely eject the SD card from the PC.
  8. Reinsert the SD card into the 3DS while the console is still powered on and still on the Extra Data screen.

If the exploit runs correctly, the console will launch SafeB9SInstaller. In current MSET9 builds, you do not need to open Mii Maker again at this stage: Mii Maker is used earlier to generate the required data, while the trigger happens from Data Management > Nintendo 3DS > Extra Data.

Installing boot9strap

  1. In SafeB9SInstaller, wait for the checks to finish.
  2. When prompted, enter the button sequence shown on the upper screen.
  3. If the upper screen is blank but the lower screen says that the crypto checks passed, use the standard sequence:
    • Left on the D-Pad;
    • Down on the D-Pad;
    • Right on the D-Pad;
    • Up on the D-Pad;
    • A.
  4. Wait until all steps are shown in green.
  5. Press A to reboot the console.

At this point, boot9strap is installed and the console should boot into the Luma3DS configuration menu.

Luma3DS Configuration and Finalization

First Luma3DS Configuration

On the first reboot after SafeB9SInstaller, the console should show the Luma3DS configuration menu.

  1. Enable Show NAND or user string in System Settings.
  2. Leave the other options unchanged unless you have a specific reason to change them.
  3. Press Start to save and reboot.

After rebooting, the console returns to the HOME Menu. The menu will not look visibly different; to verify Luma3DS, open System Settings and check that the version starts with Sys instead of Ver.

Important: before running the full finalization process, remove MSET9 as described in the Removing the Exploit section. Removing it restores the normal data profile and prevents applications from crashing.

Finalize Package

After removing MSET9, use the finalize package to install the essential tools.

  1. Power off the console.
  2. Insert the SD card into the PC.
  3. Copy finalize.romfs to the root of the SD card.
  4. Open the luma folder on the SD card.
  5. Create the payloads folder if it does not already exist.
  6. Copy x_finalize_helper.firm to /luma/payloads/.
  7. Reinsert the SD card into the 3DS.
  8. Hold X and, while continuing to hold it, power on the console.
  9. Wait for Finalizing Setup Helper and then GodMode9 to launch.
  10. When GodMode9 shows the drive list, press Home.
  11. Select Scripts....
  12. Select finalize.
  13. Follow the on-screen instructions until the Setup complete! message appears.
  14. Press A to power off the console.

This process automatically installs essential software such as FBI, Universal-Updater, Homebrew Launcher Loader, Anemone3DS, Checkpoint, ftpd, and GodMode9. When finished, copy the /gm9/backups/ folder to your PC and store it somewhere safe: it contains critical console backups.

Removing the Exploit

Removing MSET9 is mandatory. If you skip this step, normal 3DS applications may fail to launch, show errors, or crash. Removing the exploit does not remove boot9strap and does not uninstall Luma3DS.

Removing the Trigger and Restoring Data

  1. Power off the console.
  2. Remove the SD card and insert it into the PC.
  3. Launch the MSET9 script:
    • Windows: MSET9-Windows.bat or mset9.bat;
    • macOS/Linux: python3 mset9.py from the root of the SD card.
  4. Select the correct model and firmware.
  5. If the status is Injected, choose option 4 to remove the trigger file.
  6. Wait for the Removed trigger file. message.
  7. Choose option 5 to remove MSET9.
  8. Wait for the Successfully removed MSET9! message.
  9. Close the script with Enter.
  10. Reinsert the SD card into the 3DS and power on the console.

After the restore, the software and user data that seemed to disappear during the base injection should be visible again. From this point on, the console boots Luma3DS normally through boot9strap.

Final Checks

  • In System Settings, the version should appear as Sys 11.17.0-50E or the equivalent regional version.
  • Holding Select while powering on should open the Luma3DS configuration menu.
  • Holding Start while powering on should open GodMode9 or the Luma3DS chainloader.
  • System applications, including Mii Maker, should launch without crashing.

Recommended operational sources for checking future procedure updates: 3DS Hacks Guide - Installing boot9strap (MSET9 CLI), 3DS Hacks Guide - Finalizing Setup, Nintendo IT - latest system update.

License

This guide is released under the MIT license.