Convert OBJ to GLB Online Free
Pack a Wavefront OBJ mesh and its MTL materials into a single binary glTF (GLB). The result is one-file, web-ready, and loads directly into Three.js, Babylon, `<model-viewer>`, and Unity.
By ChangeThisFile Team · Last updated: March 2026
ChangeThisFile converts Wavefront OBJ to binary glTF (GLB) by parsing the OBJ mesh, reading the companion MTL material file (if present), translating Phong material parameters into glTF's PBR metallic-roughness workflow, and packing geometry plus textures into a single GLB container. Powered by Assimp on the server. Note: OBJ's legacy Phong materials approximate but don't perfectly match PBR. Free, encrypted upload, files auto-deleted after conversion.
Convert Wavefront OBJ to GLB (Binary glTF)
Drop your Wavefront OBJ file here to convert it instantly
Drag & drop your .obj file here, or click to browse
Convert to GLB (Binary glTF) instantly
Wavefront OBJ vs GLB (Binary glTF): Format Comparison
Key differences between the two formats
| Feature | OBJ | GLB |
|---|---|---|
| Format type | Plain text + MTL companion | Binary container (glTF 2.0) |
| Materials | Legacy Phong (Ka/Kd/Ks) | PBR metallic-roughness |
| Animations | Not supported | Channels, samplers, skins |
| Distribution | Multiple files (OBJ + MTL + textures) | Single binary file |
| Web suitability | Multiple HTTP fetches | One fetch — ideal for the web |
| File size | Verbose (text) | Compact (binary) |
| Ecosystem | Universal legacy | Modern web + game engines |
When to Convert
Common scenarios where this conversion is useful
Modernizing legacy 3D assets
Old OBJ models from libraries or repositories don't load directly in web viewers. Convert to GLB to drop into Three.js, Babylon, or `<model-viewer>`.
Shipping models to AR/VR experiences
WebXR, USDZ converters, and most AR runtimes prefer GLB. Convert your OBJ once and ship the GLB to every target.
Bundling textures for distribution
OBJ + MTL + textures = a fragile multi-file bundle. GLB packs everything into one binary so nothing gets lost in transit.
Game engine ingest
Unity, Unreal (via glTFast/plugins), Godot, and Babylon Native all ingest GLB faster and more reliably than OBJ.
Who Uses This Conversion
Tailored guidance for different workflows
For Web Developers
- Modernize an OBJ from a 3D model library for use in a Three.js scene
- Pack OBJ + MTL + textures into a single GLB for cleaner CDN delivery
- Prepare a 3D asset for `<model-viewer>` or an AR Quick Look pipeline
For Game Developers
- Convert OBJ assets from a marketplace into GLB for Unity's glTFast importer
- Pre-process legacy OBJ libraries into GLB to streamline runtime loading
- Bridge OBJ output from an older modeling tool into a modern game pipeline
How to Convert Wavefront OBJ to GLB (Binary glTF)
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1
Upload your OBJ bundle
Drop your `.obj` file. If you have MTL materials and textures, zip them together first and upload the zip. Up to 50MB total.
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2
Server-side conversion
Assimp parses the OBJ, resolves MTL references, translates Phong material parameters to glTF PBR metallic-roughness (diffuse → base color, specular → approximated metallic-roughness), and packs everything into a single GLB.
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3
Download the GLB file
Your `.glb` file is delivered as a download. Uploaded files are deleted from disk immediately after the response.
Developers: convert via API →
Frequently Asked Questions
If you want materials and textures in the output GLB, yes — zip the `.obj`, `.mtl`, and texture files together and upload the zip. If you upload just the `.obj`, you'll get a textureless GLB.
Assimp approximates: diffuse (Kd) and the diffuse texture (map_Kd) become base color. Specular (Ks) is rolled into a metallic-roughness estimate. Bump/normal maps (map_bump / map_Kn) map to glTF normal textures. The approximation is good enough for visual parity but isn't a physically rigorous translation.
Yes. Positions, normals, and UVs all round-trip through GLB. If your OBJ lacks normals, Assimp can compute smooth normals on the fly.
Yes. Standard GLB output, valid glTF 2.0, compatible with every major glTF 2.0 loader.
OBJ has no animation, so the output GLB is a static mesh. If you need animation, OBJ is the wrong source format — start with FBX, glTF, or a tool that exports animated GLB directly.
Yes. Referenced textures are pulled in and embedded in the GLB's BIN chunk. No external image files needed at runtime.
Assimp is a large native library; a browser-only build would mean a multi-megabyte WASM download. Server-side keeps the page light and the importer current.
50MB total upload on the anonymous endpoint, 5 requests per minute per IP. Use the authenticated /v1/convert API for larger files.
Yes. HTTPS upload, ephemeral temp directory, files deleted immediately after the conversion response. Contents are not logged.
Related Conversions
Need to convert programmatically?
Use the ChangeThisFile API to convert Wavefront OBJ to GLB (Binary glTF) in your app or script. Free tier included.
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