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OBJ to GLB: How to Convert (and What Gets Lost)
Going from OBJ to GLB is a lossy step in some directions and a no-op in others. Here is what each format actually carries, what survives the conversion, and the methods worth using in 2026.
What is OBJ?
OBJ is a plain-text geometry format that has barely changed since the early 1990s. It stores vertices, faces, vertex normals, and texture coordinates, with materials kept in an accompanying .mtl file. It is human-readable, easy to parse, and supported essentially everywhere — which is why it remains the most common interchange format between modeling tools.
- Plain-text format, line-based and trivially diffable
- Materials live in a separate .mtl file alongside the .obj
- Supports vertex colors, UVs, normals, and named groups
- No animation, no rigging, no scene hierarchy
What is GLB?
GLB is the binary container for glTF — the format Khronos Group designed to be the "JPEG of 3D". A single .glb file bundles mesh, materials, textures, animations, and skins into one self-contained asset, optimized for transmission over the network. It is the native format of WebGL, WebGPU, and AR viewers like Apple Quick Look and Android Scene Viewer.
- Single self-contained binary file (mesh + textures + animations)
- Native to web 3D, AR, and metaverse pipelines
- PBR material model (base color, metallic/roughness, normal, emission)
- Supports skinning, morph targets, and keyframe animation
How to convert OBJ to GLB
OBJ and GLB have overlapping capabilities, and most converters get the geometry right. The differences show up around materials, units, axis orientation, and what each tool downstream expects.
- Blender (free, all platforms). Open Blender, File → Import → OBJ (.obj), then File → Export → GLB (.glb). Blender has native importers and exporters for every format on this page except STEP (which needs the optional CAD Sketcher addon or a separate STEP-to-mesh pass). The export dialog exposes the settings that matter: scale, axis orientation, and whether to embed materials and animations.
What gets preserved, what gets lost
Geometry-wise, OBJ and GLB carry the same essential data, so this conversion is reasonably lossless.
Common use cases
- Embedding a 3D model in a web page with model-viewer or Three.js
- Publishing to AR (Apple Quick Look, Android Scene Viewer)
- Sending an asset to a colleague who works in a web 3D pipeline
Questions
Is OBJ to GLB conversion lossy?
For the geometry, no — vertices and faces map cleanly. There may be small precision differences depending on the tool, but nothing visible. Color, texture, and animation data depend on the specific source and destination — see the preservation notes above.
Can I do this conversion online for free?
Yes — for files under ~50MB, browser-based converters handle this pair quickly. For larger files or anything proprietary, use Blender locally so the file does not leave your machine. Both options are free.
Can Automatic3D output GLB directly?
Automatic3D's primary output is STL, optimized for 3D printing. For GLB-specific workflows, convert from the STL using one of the methods above.