NBTExplorer can read:
- Standard NBT files (e.g. level.dat)
- Schematic files
- Uncompressed NBT files (e.g. idcounts.dat)
- Minecraft region files (*.mcr)
- Minecraft anvil files (*.mca)
- Cubic Chunks region files
NBTExplorer is a Windows .NET application, and requires .NET framework 2.0 or higher to run.
NBTExplorer has been tested for compatibility with recent Mono runtimes. Minimally, your system needs the mono-core and mono-winforms packages, or whatever set of packages is equivalent.
A Mac-specific version of NBTExplorer is available with a native UX. It is compatible with Mac OS X 10.7 or higher. It will not run on 10.6, sorry.
As of August 22, 2013, I've begun signing NBTExplorer with an Apple Developer ID certificate. If you have GateKeeper configured to only allow software from the App Store, then you will need to change GateKeeper to allow running signed downloaded applications, or following these instructions to bypass GateKeeper:
If you have problems with the native client or you're running OS X 10.6 or older, you can still run the Windows version of NBTExplorer on your Mac by following the Linux instructions and installing the Mono runtime. You may still need to disable GateKeeper quarantine on the downloaded files.
Download: Windows / Linux (Version 2.6.1)
Download: Mac (Version 2.0.3)
Project Page: Github
I recommend backing up worlds before modifying them with this tool.
Frequently Asked Questions
Q: NBTExplorer didn't save my changes -- why?
A: It's possible you forgot to save. The more likely answer is NBTExplorer did save your changes, and if you were to immediately re-open your world in NBTExplorer, you would see that your changes are still there. Instead, Minecraft erased or ignored your changes when you loaded your world. The most common trap is editing player settings or inventory on a single-player world and making your changes in a <player>.dat file instead of in level.dat. Minecraft will overwrite your <player>.dat file on load with the contents of the player tag in level.dat.
Q: I'm on Windows and NBTExplorer crashed on start / didn't run.
A: Did you get a message box listing one or more exceptions? Reply to this thread with the information so you can be better helped.
If you didn't get any message box though, or you only received a standard "program has stopped working" message box, then you have deeper issues with your .NET environment. Do any other .NET programs run on your computer? If yes, then try deleting the NBTExplorer.exe.config file that was installed / came with the zip. This will cause NBTExplorer to prefer the .NET 2.x/3.x framework over the 4.x framework, and may allow the program to run if your .NET 4.x framework is toast. You should still do something about that, of course.
Q: The Mac version doesn't run on my Mac!
A: If you're running OSX 10.6.x or earlier, the Mac version is confirmed to not work. It has been tested and confirmed to work for people on 10.7.x and 10.8.x, although that may still not be a guarantee that it will work for you, or that it will be bug-free.
If you're having problems running the Mac-specific version of NBTExplorer, there is still a high probability that you can run the Windows/Linux version instead. thhinds has posted a more detailed set of instructions here. It won't be as pretty -- you'll get a very crude looking version of Windows UI styling instead of native OSX styling, but it should still do the job. I can't do anything about this unless an experienced Cocoa developer that also has some .NET/Mono experience is willing to step up and help me determine why it won't run on older versions of OSX.
Q: When I run the Mac version, I see: OSStatus error -67053
A: It has been reported that this is caused by Gatekeeper disallowing NBTExplorer from running because it is not a properly signed application. Please refer to the instructions in the "Mac Users" section above for bypassing GateKeeper's check. NOTE: As of August 22, 2013, I have begun signing NBTExplorer. Try downloading the latest version first.