NBT format


Info

The Named Binary Tag format is used by Minecraft for the various files in which it saves data. The format is described by Notch in a very brief specification. The format is designed to store data in a tree structure made up of various tags. All tags have an ID and a name. The original known version was 19132 as introduced in Minecraft Beta Beta Starting version Beta 1.0 (Dec. 20, 2010) Latest version Beta 1.9-pre6 (Nov. 13, 2011) Paid Yes These versions are available to play in the launcher. Be that as it may, please note that these versions contain bugs. You ll minecraft 1.3, and since then has been updated to 19133 with Anvil See the file format. For the item repair block, see Anvil. The Anvil 1] file format was officially introduced in Minecraft 1.2. It brings a list of changes and improvements over from minecraft , with the addition of the Int Array tag. The NBT format dates all the way back to Minecraft Indev Indev Starting version 0.31 (Dec. 23, 2009) Latest version Minecraft Indev (Feb. 23, 2010) Paid Yes This page contains content that is no longer in the game. These featuresSpecial attraction only exist in outdated versions of minecraft with tags 0 to 10 in use.

TAG definition

A tag is an individual part of the data tree. The first byte in a tag is the tag type (ID), followed by two bytes for the length of the name, then the name as a string in UTF-8 format (Note TAG_End is not named and does not contain the extra 2 bytes; the name is assumed to be empty). The name of tags may contain spaces, although Minecraft itself never saves tags with spaces in the names. At long last, depending on the type of the tag, the bytes that follow are part of that tag`s payload. This table describes each of the 12 known tags in version 19133 of the Named Binary Tag format:

ID Icon Tag Type Payload Description Storage Capacity
0 TAG_End None. Used to mark the end of compound tags. This tag does not have a name, so it is only ever a single byte 0. It may also be the type of empty List tags. N/A
1
TAG_Byte 1 byte / 8 bits, signed A signed integral type. Sometimes used for booleans. Full range of -(27) to (27 - 1)
(-128 to 127)
2
TAG_Short 2 bytes / 16 bits, signed, big endian A signed integral type. Full range of -(215) to (215 - 1)
(-32,768 to 32,767)
3
TAG_Int 4 bytes / 32 bits, signed, big endian A signed integral type. Full range of -(231) to (231 - 1)
(-2,147,483,648 to 2,147,483,647)
4
TAG_Long 8 bytes / 64 bits, signed, big endian A signed integral type. Full range of -(263) to (263 - 1)
(-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)
5
TAG_Float 4 bytes / 32 bits, signed, big endian, IEEE 754-2008, binary32 A signed floating point type. Precision varies throughout number line;
See Single-precision floating-point format. Maximum value about 3.4*1038
6
TAG_Double 8 bytes / 64 bits, signed, big endian, IEEE 754-2008, binary64 A signed floating point type. Precision varies throughout number line;
See Double-precision floating-point format. Maximum value about 1.8*10308
7
TAG_Byte_Array TAG_Int`s payload size, then size TAG_Byte`s payloads. An array of bytes. Maximum number of elements ranges between (231 - 9) and (231 - 1) (2,147,483,639 and 2,147,483,647), depending on the specific JVM.
8
TAG_String TAG_Short`s payload length, then a UTF-8 string with size length. A UTF-8 string. It has a size, rather than being null terminated. 32,767 bytes interpretable as UTF-8 (see UTF-8 format; most commonly-used characters are a single byte).
9
TAG_List TAG_Byte`s payload tagId, then TAG_Int`s payload size, then size tags` payloads, all of type tagId. A list of tag payloads, without repeated tag IDs or any tag names. Due to JVM limitations and the implementation of ArrayList, the maximum number of list elements is (231 - 9), or 2,147,483,639. Also note that List and Compound tags may not be nested beyond a depth of 512.
10
TAG_Compound Fully formed tags, followed by a TAG_End. A list of fully formed tags, including their IDs, names, and payloads. No two tags may have the same name. Unlike lists, there is no hard limit to the amount of tags within a Compound (of course, there is always the implicit limit of virtual memory). Note, be that as it may, that Compound and List tags may not be nested beyond a depth of 512.
11
TAG_Int_Array TAG_Int`s payload size, then size TAG_Int`s payloads. An array of TAG_Int`s payloads. Maximum number of elements ranges between (231 - 9) and (231 - 1) (2,147,483,639 and 2,147,483,647), depending on the specific JVM.
12
TAG_Long_Array TAG_Int`s payload size, then size TAG_Long`s payloads. An array of TAG_Long`s payloads. Maximum number of elements ranges between (231 - 9) and (231 - 1) (2,147,483,639 and 2,147,483,647), depending on the specific JVM.

The List and Compound tags can be and often are recursively nested. It should also be noted that, in a list of lists, each of the sub-lists can list a different kind of tag.

Videos

File Format

An NBT file is a GZip`d Compound tag, name and tag ID included. Some of the files utilized by Minecraft may be uncompressed, but in most cases the files follow Notch`s original specification and are compressed with GZip. In the Xbox 360 Edition Xbox 360 Edition Author(s) Mojang AB 4J Studios Platform(s) Xbox 360 Written in C++ 1] Latest version TU53 Released Digital - Marketplace May 9th, 2012 Retail Disc - DVD s Jun. 4th, 2013 Rating(s) (online interactions minecraft , chunks Visualization of the ground portion of a single chunk. The entire chunk extends up to a height of 256. Chunks are 16 × 16 × 256 segments of the Minecraft worlds. Contents 1 Generation 1.1 minecraft are compressed with XMemCompress, a variation of an LZX compression algorithm. There is no header to specify the version or any other information - only the level.dat In Minecraft 1.0, each level is its own folder. A level folder is often identified by having a level.dat file, along with other subfolders to store the maps and regions of the level. Level folders file specifies the version.

As used in Minecraft

Minecraft`s use of the NBT format is odd at times. In some instances, empty lists may be represented as a list of Byte tags rather than a list of the correct type, or as a list of End tags in newer versions of Minecraft, which can break some older NBT tools. Additionally, almost every root tag has an empty name string and encapsulates only one Compound tag with the actual data and a name. For instance:


  • The root tag for most Minecraft NBT structures.

    • ℂ₂⃂SomeName: The only tag contained within the root tag - it has a name and contains all the actual data.

Another noticeable oddity is that, although the original specification by Notch allows for spaces in tag names, and even the example uses spaces in the tag names, Minecraft has no known files where any tags have spaces in their names. There is also inconsistent use of letter case, mostly either lowerCamelCase or UpperCamelCase, but sometimes even in all lowercase.

Uses

Software

Mojang has provided sample Java NBT classes for developers to use and reference as part of the source code for the McRegion -> Anvil converter. Other than this, the community has developed programs to view and modify compressed and uncompressed NBT files:

Name NBT Version Description Screenshot
MineBack Ultimate 19133 MineBack Ultimate provides a full NBT editor supporting all available types of NBT format file (Map, Level, World etc.). It comes with a modern GUI and many helper functions. MineBackNBTEditor.png
NBTEdit 19132 Allows for viewing and modifying NBT files via a Windowsis a separate viewing area on a computer display screen in a system that allows multiple viewing areas as part of a graphical user interface tree control. It is outdated not only from being an NBT version behind, but because it does not support multiple tags with the same name and it forces incorrect ranges on some types, and it lacks support for uncompressed NBT files. NBTEdit Level.Dat.png
NBTExplorer The contents of this page are not supported by Mojang AB, the Minecraft Wiki, the Minecraft IRC channel or the Minecraft Forums. See a third-party program. For the official Minecraft program, see minecraft - Forum Post 19133 Inspired by and based on NBTEdit, this program allows viewing and editing of NBT files via a Windowsis a separate viewing area on a computer display screen in a system that allows multiple viewing areas as part of a graphical user interface tree control. It supports compressed and uncompressed NBT files, and allows for direct editing of the NBT structures in MCRegion The Region file format is a storage format for Minecraft chunks introduced in Minecraft Beta 1.3, in which groups of 32×32 chunks are stored in a region file. This file format took the place of minecraft and Anvil See the file format. For the item repair block, see Anvil. The Anvil 1] file format was officially introduced in Minecraft 1.2. It brings a list of changes and improvements over from minecraft files, level.dat In Minecraft 1.0, each level is its own folder. A level folder is often identified by having a level.dat file, along with other subfolders to store the maps and regions of the level. Level folders , etc. NBTExplorer.png
NBT grammar for Synalyze It! 19132 Using this grammar Synalyze It! displays a color-coded hex dump along with the parsed tag tree. Currently only uncompressed files are supported. Synalyze-It-NBT-decoded.png
NEINedit 19132 NBT editor for mac with a text-based tree structure. NEINedit.png
NBT2YAML 19133 nbt2yaml presents a command line interface for reading and editing Minecraft NBT files using a custom YAML format. It also includes a Python API for parsing and writing NBT files to/from a simple Python data structure.
webNBT 19133 webNBT is an NBT-editor that runs in modern browsers without requiring the user to download an application or use third-party browser plugins (like Flash or Java).