3DS TO CIA - Katsu

From GameBrew

3DS TO CIA by Katsu
Last Updated2015/03/20
TypeFile Operation

3DS to CIA is a tool designed to convert ROM dumps into installable CIA files, with features for modifiers who want to translate or edit content.


  • 7.x Support.
  • Region Free fix.
  • Offers injecting original EXHEADER.
  • Offers spoofing Firmware to 4.x.
  • Offers using your own .rsf (no exinjector).
  • Download Play Support.
  • Includes Manual when detected.
  • Auto RSF - big thx @ Vappy.
  • Decrypts manual created cia.
  • Rebuild .3DS (Target -G).
  • Allows to de/re crypt romfs for editing purpose.
  • Quick rebuild .3DS per Folder drag n drop.
  • Quick rebuild .cia per Folder drag n drop (requires .3ds/.cci).
  • Supports decrypted .3ds from rxTools.



  • A 3DS capable of generating XORPADS for legit 3DS to CIA.
  • Python 2.7.
  • Add Path to Windows Enviroments (e.g. c:\windows\system32;c:\python27).

Included in Package are:

  • RomFS Builder - Thx @ SciresM.
  • ExInjector - Thx @ piratesephiroth.
  • 3DSExplorer.
  • Notepad++.
  • ctrKeyGen.
  • Launcher.dat.
  • slot0x25KeyX (you need to insert the key, google it).

User guide

From .3ds to cia:

  • Create your xorpads and put all files into 3ds to cia dir next to Make batch.
  • Drag n drop .3ds/.3dz on Make batch.
  • Choose your Options and start.

Decrypt selfmade cia (no legit cia):

  • Drag and drop your cia on Make batch.

Extract decrypted .3ds (no legit/rebuilded/regenerated 3ds):

  • Rename your .3ds to <filename_modified.3ds>.
  • Drag and drop your .3ds on Make batch.

Quick rebuild from files inside folder:

  • Make sure all files are in the same Folder (romfs.bin/banner.bin/code.bin/exheader.bin/icon.bin/logo.bin/.rsf***).
  • Edit your .rsf to work as .3ds, not .cia.
  • Drag and drop your Folder on Make batch.
  • (***As for rebuilding .3ds, a working file depends on your Skill to modify your .rsf.)

Mostly there is not much to change, make sure to change at least:

  • Title / CompanyCode / ProductCode / UniqueId / MediaSize.
  • MediaType / CardDevice / ExtSaveDataId / SaveDataSize.
  • And if needed: JumpId.

You can take the sample-rsf-reb.txt and fill in the needed Details, from exheader.txt / info.txt and "rom_tool -i <gamename.3ds>".

You will see green texts when everything is running smoothly, if something went wrong the texts will be displayed in red.






  • Fixed a small bug to keep original.
  • Speeded up cia repack.


  • Rebuilding from _modified.3ds / .cia got completly rewritten.
  • Changed main Menu to allow more options.
  • Rebuild .3ds will now includes original Exheader to keep compatibility to updates/dlc.
  • Excract ROMFS is now aviable for all main functions.
  • Added option to keep decrypted files.
  • Original file is now in "original" folder after using 3ds_to_cia.
  • Some cleanup from old code / minor bugfixes.


  • Fixed Bug for .rsf generation.
  • Added libeay32.dll.


  • Added Decrypt9 Bootstap Version for Ninjhax (new3DS .3dsx).
  • Added Option 8 "check .rsf for auto generation" (manual check before building cia if rsf fails).
  • Speedup when DLP and or Manual is included.
  • Minor changes and Bugfixes.

External links