Minecraft versions

The target version is the Minecraft version you build the map for. The block list, textures and export checks follow this version. The default is 1.21.11. The editor finds the client jar of the same version in the launcher folders on this PC and reads the vanilla textures from it. The jar is never copied or extracted.

How to open

What	Where
Choose the target version	Target version dropdown on the right of the menu bar
From Project Settings	Edit › Project Settings… › World › Target version
Rescan the launcher folders	File › Rescan launcher folder (version list)
Pick a jar manually	File › Load jar…
Build a block list	File › Build block list from server jar… (target version)

Quick start

Open the Target version dropdown on the right of the menu bar.
Pick a version from the list. Each row shows the version, the launcher it was found in, and “list available” (block list cache).
The editor switches textures to that version’s client jar.
The notification shows “Target version 1.21.11: N block types · N states”.
If the world has blocks that do not exist in that version, they are also listed in the notification.

How the jar is found

The editor looks for launcher folders in the order below. If the same version is in several places, the earlier one is used.

Order	Launcher	Folder searched
1	CurseForge	`%USERPROFILE%\curseforge\minecraft\Install\versions`
2	Official launcher	`%APPDATA%\.minecraft\versions`
3	Prism	`%APPDATA%\PrismLauncher\libraries\com\mojang\minecraft`
4	MultiMC	`%APPDATA%\MultiMC\libraries\com\mojang\minecraft`
5	TLauncher	`%APPDATA%\.tlauncher\legacy\Minecraft\game\versions`
6	Modrinth	`%APPDATA%\ModrinthApp\meta\versions`, etc.
7	Picked manually	Jars picked with Load jar… (the last 12 are remembered)

Only vanilla versions are found. Mod loader folders such as forge, neoforge, fabric, quilt and optifine are excluded.
If the jar for the chosen version is not on this PC, the textures stay on the current jar and you are notified.
If you downloaded a new version with a launcher, click File › Rescan launcher folder (version list).

Block list (server report)

The authoritative source for block names, properties and default states is the data report (blocks.json) of that version’s server jar.

Click File › Build block list from server jar… (target version).
Pick the Minecraft server jar for that version.
The report is generated with java (tens of seconds). The list is kept in the user cache.

java is required. If it cannot be found, you are told to set JAVA_HOME or add java to PATH.
Without a list, the block list from the client jar is used. Property value checks are weaker in that case.
A red name in the Content Browser is a block not in the target version’s list.

Drawing blocks from other versions

Since 0.9.10: Blocks that are not in the chosen jar are drawn with that block’s art instead of a placeholder box.

Case	How it is drawn
Block that was only renamed	Drawn with the name used in that jar (table below).
Block not in that version (a block from a newer version)	The art is taken from a newer jar on this PC. The block list stays that of the target jar.
No newer jar either	Drawn as a name-colored box.

Example notification: “2 block types not in this jar (…) — shown with 1.21.11 art (they don’t exist in this game version)”. Only the art is borrowed, so those blocks do not exist in the game of the target version.

Old name	New name	Changed in
`sign`	`oak_sign`	1.14
`wall_sign`	`oak_wall_sign`	1.14
`grass_path`	`dirt_path`	1.17
`grass`	`short_grass`	1.20.3
`chain`	`iron_chain`	1.21.9

What works now

Feature	What works now
Target version list	All vanilla versions found in the launcher folders on this PC (including 26.x) and versions with a block list cache
Textures · drawing blocks from other versions	Among jars on this PC. The rename table was verified with the 1.18.2 · 1.20.1 · 1.21.1 · 1.21.11 · 26.1.2 · 26.2 jars.
Export target versions (.schem · .npbuild)	1.20.1 · 1.20.4 · 1.20.6 · 1.21 · 1.21.1 · 1.21.3 · 1.21.4 – 1.21.11
Minecraft world save	1.20.1 and later. Props from 1.21.4. 26.x is written in 1.21.11 format and the game upgrades it.
World import	Worlds from 1.18 and later
Resource pack · shader pack	Based on 1.21.11 (resource pack pack_format 75, items in the 1.21.4+ format)
AI connection block checks	1.21.11 by default

Still planned

The target range for cross-version compatibility is 1.13 – 26.x. The following do not work yet.

Plan	Current status
Exporting for 1.13 – 1.19	The export target list starts at 1.20.1. 1.18.2 is import only.
Matching blocks whose properties changed (1.16 wall low/tall, 1.17 cauldron water, etc.)	Not in the rename table.
Blocks whose meaning changed (1.14 `stone_slab`, etc.)	Not handled.
A tool to rename world blocks to the target version’s names	Not in the UI yet. For now, other names are used only for drawing.
A 26.x-specific export format	The 26.x format values have not been confirmed yet.
Jar verification of the 1.14 · 1.17 rename rows	Based on public sources; not yet verified with those versions’ jars.

Options

Setting	Where	Default
Target version	Menu bar · Project Settings	1.21.11 (remembers the last chosen version)
Block list	Block list in the export window	Cache · automatic if empty
Missing blocks	Export window	Warning table only (keep)

Shortcuts

There are no dedicated shortcuts for this feature.

Tips / notes

The target version is saved in the project (world file). Opening another world switches to the version saved in that world.
Vanilla textures are read only from the jar on the user’s PC. The editor does not distribute vanilla art.
If there is no jar at all, blocks are shown as name-colored placeholders. Running that version once in the official launcher creates the jar.
On export, blocks not in the target version are warned about, replaced or blocked according to the Missing blocks setting (Export and import).