Convert GLB to OBJ

Why convert GLB to OBJ?

GLB packs a model, its materials and textures into a single binary file, which is convenient on the web but awkward in older or simpler tools. Converting GLB to OBJ gives you a format that nearly every 3D application can read, which is why people do it for Blender workflows, legacy renderers, school software and 3D printing preparation. The mesh and UV coordinates carry over. Textures from the GLB are written out next to the OBJ and referenced by an MTL material file, so keep them together. PBR properties such as roughness and metallic maps do not have a standard place in OBJ and are simplified. The scene is written as a set of named objects.

How to convert GLB to OBJ

1. Drop your GLB file (with its textures, if separate) onto the converter — it opens in your browser, nothing is uploaded.
2. Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
3. Choose OBJ as the output and click Convert. Several files download as one ZIP.

What carries over from GLB to OBJ

What changes

• PBR materials are reduced to basic colour and texture; roughness, metallic and emissive settings are lost.
• Animations, skins and morph targets are dropped.
• Metres in the GLB are converted to millimetres when you choose that option; OBJ itself stores no unit.
• Y-up orientation stays as it was unless you choose to rotate the model.

Tips

• Unzip all outputs into one folder so the OBJ can find its MTL and texture images.
• If you plan to print, STL or 3MF is usually the better target than OBJ.
• In Blender, import with the correct forward and up axes to avoid a rotated model.
• Check that the dimensions make sense; a GLB authored for AR may be modelled at real-world metre scale.

About GLB files

GLB is the binary container for glTF 2.0, the format the Khronos Group describes as the JPEG of 3D. One .glb file bundles a JSON scene description, binary mesh buffers and embedded images, so nothing can go missing in transit. The format was designed for efficient delivery and loading on the web, and it is now used by Three.js, Babylon.js, model-viewer, Google Search 3D results, Meta platforms, Unity and Unreal importers, and many marketplaces such as Sketchfab. glTF defines a physically based metallic-roughness material model, a node hierarchy, cameras, skins and animations. Coordinates are in metres with +Y up and a right-handed system. It is excellent for display and game assets, but it is a presentation format rather than a manufacturing one, so print workflows usually convert it first.

About OBJ files

OBJ comes from Wavefront Technologies' Advanced Visualizer software in the 1980s, and it has outlived the product. A file is plain text: lines starting with v define vertices, vt texture coordinates, vn normals, and f faces that reference those lists by index. Faces may be triangles, quads or larger polygons, and the g and o keywords group faces into named objects. Appearance is not in the OBJ at all; a line called mtllib points to a separate .mtl file that lists materials with diffuse colours and texture image names. The format is verbose, has no official unit and no scene hierarchy or animation, but it is trivial to read and write. That is why scanners, photogrammetry tools, sculpting programs and game pipelines still use it to move static meshes around.

3D printing notes

Few slicers open GLB directly, so people convert it to STL or 3MF. The two things to get right are scale and orientation. GLB is metres and Y-up, while slicers expect millimetres and Z-up; a 0.1 m figure becomes a 0.1 mm speck if the numbers are read as millimetres. MeshShift multiplies by 1000 on export to STL or 3MF by default, which you can switch off, and rotates the Y-up axis so the model sits flat on the bed. Game-ready GLB files often have open edges, intersecting parts and thin shells, so run the print check and repair before slicing. Colours can be kept when writing 3MF.

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