Will my PBR materials survive an OBJ conversion?

Only in part. The diffuse colour and a flattened base-colour texture are carried across into the .mtl. Metallic, roughness, normal, occlusion and emissive maps have no MTL equivalent and are dropped.

Why do I get a ZIP instead of a single .obj?

Because a materialised OBJ model is several files: the .obj, its .mtl and the PNG textures the .mtl references. GLBKit zips them together so the relative paths stay valid.

Does vertex colour survive?

No. OBJ has no standard vertex-colour field, so per-vertex colour from the GLB is not written.

GLB to OBJ Converter

Name: GLB to OBJ Converter
Author: GLBKit

Convert a GLB to Wavefront OBJ with a matching .mtl and flattened diffuse textures. Processed locally in your browser.

Drag & drop your GLB file here

or click to browse

Supported Formats

.glb.gltf.obj.fbx.stl.ply.3mf.off.zip

Format Information

Source Format

GLB.glb

GLB (glTF Binary)

GLB is the binary packaging of glTF 2.0. Meshes, materials, image textures, animation and the node hierarchy are all written into one file, so an asset can be dropped into an engine or a web page without shipping a folder of sidecar files.

What it carries: Vertex positions, normals, UVs and vertex colours, full PBR materials (base colour, metallic/roughness, normal, occlusion, emissive), embedded image textures, node hierarchy, skinning, morph targets, keyframe animation, cameras and lights.

Open a GLB file in the viewer

Target Format

OBJ.obj

OBJ (Wavefront)

The Wavefront OBJ format is a plain-text mesh description that has been the default interchange format for computer graphics since the 1990s. Geometry lives in the .obj file; colour and texture references live in a companion .mtl file.

What it carries: Vertex positions, normals, texture coordinates and polygon faces, plus what MTL can express: a diffuse colour, opacity, shininess and a single diffuse texture map. There are no PBR metal/roughness values, no normal maps, no vertex colours and no animation.

Open a OBJ file in the viewer

About this conversion

This conversion strips a modern PBR scene back to the oldest widely supported mesh format. GLBKit writes the .obj geometry and, when the scene has materials, a matching .mtl plus flattened diffuse textures, packaged as a ZIP.

Why convert GLB to OBJ

Open a GLB in a tool that only speaks OBJ — many CAD, sculpting and 3D-printing utilities still do.
Hand geometry to a shader, OpenGL tutorial or custom renderer that writes its own OBJ parser.
Get a readable, diffable .obj for a repository that stores simple meshes as text.

What happens during the conversion

Geometry

Vertex positions, texture coordinates, normals and faces are written through. Because OBJ has no scene graph of its own, node transforms are baked into the vertex positions and the hierarchy is flattened into a single object list.

Materials and textures

This is where fidelity is lost. Each material becomes an .mtl entry with a diffuse colour (Kd), an opacity value and a map_Kd pointing at a PNG re-encoded from the material's base-colour texture. Metallic, roughness, normal, occlusion and emissive maps have no MTL equivalent and are dropped.

Animation

A GLB can hold keyframe animation, skinning and morph targets, and OBJ has no field for any of it. What you get back is a single static pose of the scene as it stood. If the rig is the part you care about, glTF is the target that keeps it, since GLB and glTF share the same animation model.

Common use cases

Feeding a legacy DCC tool or a slicer that expects OBJ.
Publishing a lightweight web demo that loads a raw WebGL OBJ loader.
Getting a material-light version of a textured asset for quick shape review.

Limitations of this conversion

Normal maps, metallic/roughness and emissive maps are discarded — the result is lit like a plain diffuse surface.
Vertex colours are not written to OBJ, so colour-per-vertex data is lost even when the source has it.
Textures are re-encoded through a canvas, so an unreadable or non-rasterisable image is silently skipped and the material falls back to its flat colour.
OBJ is not a scene format: cameras, lights, skinning and animation have nowhere to go.

How to convert GLB to OBJ

Three steps in the browser. Nothing is uploaded to a server, so an unwieldy file is limited only by your own device's memory.

STEP 1

Drop in your .glb

The .glb arrives as a single self-contained file, so there is no archive to unpack.

STEP 2

Convert to OBJ

Geometry, UVs and normals are written, and materials are converted to .mtl entries with flattened diffuse maps.

STEP 3

Unpack the ZIP before opening the result

A textured model arrives as .obj + .mtl + PNGs. Unpack them into one folder or the material references will not resolve.