Data version

A data version, also known as a world version,server.jar or javabridge library source, located in class com.mojang.bridge.game.GameVersionAs appeared in the version.json format. is a positive integer used in a world saved data to denote a specific version, and determines whether the player should be warned about opening that world due to client version incompatibilities.
== Usage ==
Upon selecting and loading a singleplayer world, the game checks if the client has a data version newer or older than the selected world. If it does, the game then prompts the user whether they want to back up their world before playing it if the world is older, or warn them that their world may become corrupted if the world is newer.
== Versioning ==
Every version of Java Edition since 15w32a, including minor releases and snapshots, has its own data version. The version takes the form of an ever-increasing positive integer unlike client versions. Data versions are necessary because client versions usually cannot be directly compared since they use different formats (i.e., "1.14" and "19w02a" cannot be compared). Data versions may skip numbers between any release.
== Storage locations ==
Data versions can be found in many different places.
=== Player data ===
In-game, the data version can be obtained using the command .
=== options.txt ===
The first line of options.txt since 1.10-pre1 displays the data version, named version.
=== level.dat ===
The data version is stored in two places inside the level.dat file of a world save: in the root compound named and also in the compound named .
* level.dat
** : Information about the level.dat file.
*** : An integer displaying the data version.
*** : Versioning information about when the world was last saved.
**** : An integer displaying the data version.
=== Region files ===
Each chunk in the region files (located in .minecraft\saves\<world name>\region named r.<region X>.<region Z>.mca) contains information about the data version when it was last saved.
* : Information about the region at exact region coordinates [x,y] (1 region = 32×32 chunks)
** : Information about the chunk at relative chunk coordinates [x1,y1], located at exact chunk coordinates [x2,y2] (1 chunk = 16×16 blocks)
*** : An integer displaying the data version.
=== .dat and .nbt files ===
All .dat and .nbt files contain the data version in their root compound of when the file was last saved.
* 
** : An integer displaying the data version.
=== version.json ===
Each Minecraft build since 18w47b also specifies its current data version in the version.json file, found in the root directory of the client and server jars.
* version.json
** : The data version of this build.
== List of data versions ==
== History ==
== See also ==
* Protocol version
* al_version
== References ==
es:Versión de datos
ja:データバージョン
ko:데이터 버전
pt:Versão de dados
ru:Версия данных
uk:Версія даних
zh:数据版本