Where does the .nbt file go?

Into your world's generated/minecraft/structures folder, or a datapack's structures folder. A structure block set to Load can then read it by name.

My model is larger than 48 blocks — what now?

Choose the chunked NBT export instead. It splits the voxelized build into several .nbt files named by their origin coordinates and downloads them as a zip, so you can place them side by side.

Do I need any mods for this?

No. Structure blocks are vanilla Java Edition, so a .nbt works on an unmodded client or server.

Are the model's textures used to choose blocks?

Yes, when the .mtl and its images are selected with the .obj. Each sampled surface colour is matched to the closest block in the palette.

Convert .obj to .nbt

Turn a 3D model into a vanilla Minecraft structure. Bloxelizer reads your .obj — with its .mtl and textures, if you select them too — voxelizes it in the browser, and exports a structure-block .nbt that needs no mods at all.

Free & unlimited

Runs in your browser

3D & layer previews

Drop a Minecraft schematic

orBrowse

We'll detect the format, let you view your build layer by layer in 2D / 3D, and let you export it to any format.

.schem

.litematic

.bp

.mcstructure

.nbt

.schematic

.mcstructurezip

.mcworld

.zip(Java world)

.prefab.json

.json

.glb

.gltf

.obj

.mtl

.stl

.bbmodel

.geo.json

.png

.jpg

.jpeg

.webp

Or paste a URL

The .obj and .nbt formats

.obj is Wavefront's plain-text mesh format: vertices and faces, with colours and textures delegated to a companion .mtl file. A structure-block .nbt is Minecraft Java Edition's own format — a block-state palette, a list of positioned blocks, and a data version — placed in-game by a structure block, which reads at most 48 blocks per axis. The conversion voxelizes the mesh onto a block grid at the size you choose, then writes those blocks into the structure palette layout vanilla expects.

How to convert .obj to .nbt

Select your .obj file — with its .mtl and texture images, if it has them — in the converter below.

Set the build size, rotation, and block palette in the preview panel, then apply.

Leave .nbt selected as the export format and download the structure.

When to use this conversion

Use this route when the build has to work in unmodded Java Edition: structure blocks, datapacks, and custom world generation all consume .nbt directly, with no WorldEdit or Litematica required.

Compatibility notes

A structure block reads at most 48 blocks per axis, so keep the build size within that if you want to place the model in one piece. For anything larger, pick the chunked NBT export, which splits the build into several origin-named .nbt files in a zip. Colours only survive if the .mtl and its textures are selected alongside the .obj.