Format Guide
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| Extension | .gltf (JSON + external assets), .glb (binary bundle) |
|---|---|
| Full name | GL Transmission Format |
| Standard | Khronos Group glTF 2.0 |
| Geometry type | Triangle mesh |
| Open standard | Yes |
| Supports PBR materials | Yes — metallic/roughness workflow |
| Supports animations | Yes — skeletal and morph target |
| Supports assemblies | Yes — scene hierarchy |
glTF (GL Transmission Format) is an open standard developed by the Khronos Group. Introduced in 2015 and reaching version 2.0 in 2017, glTF is designed for efficient delivery of 3D scenes to web browsers and real-time applications. It stores mesh geometry, PBR (Physically Based Rendering) materials, textures, animations, and scene hierarchy in a JSON-based format. GLB is the binary container variant that packages the JSON and all binary data into a single .glb file. glTF has been called the “JPEG of 3D” — the format most widely supported by web renderers, AR/VR platforms, and e-commerce product viewers.
glTF is the native format for Three.js, Babylon.js, and model-viewer. Shopify, Amazon, and Google use glTF/GLB for interactive 3D product visualization.
Apple AR Quick Look (iOS), Google SceneViewer (Android), and WebXR all natively load GLB files. Product AR experiences on mobile use GLB almost exclusively.
Unreal Engine, Godot, and Babylon.js natively import glTF. It is the preferred format for real-time scenes due to its compact size and GPU-ready structure.
When you target the web, AR, or three.js, mesh size is everything. 3D CAD Converter can apply Google Draco geometry compression to glTF and GLB output, shrinking models dramatically while keeping visual quality.
Draco compression is a desktop option: enable the Draco compression checkbox in the glTF settings and pick a compression level to shrink GLB files for the web. How to reduce glTF file size
Turning a CAD model or mesh into a web-ready glTF or GLB file takes three steps in 3D CAD Converter.
Load your model
Drag a STEP, OBJ, FBX, STL or IGES file into the app, or drop a whole folder to convert many parts at once.
Choose glTF or GLB
Pick glTF for a JSON file with external assets, or GLB for a single self-contained binary. Open the glTF settings to set the mesh quality and, if you target the web, enable Draco compression.
Convert
Click Convert and the app writes ready-to-use glTF/GLB with PBR materials. Output is fully offline, so your models never leave your machine.
Prefer the command line? The bundled CLI converts and batches glTF/GLB too:
Add --units or --tessellation to control scale and mesh density. To compress GLB output with Draco, use the desktop glTF settings.
glTF is often called the JPEG of 3D: it is the format browsers, AR viewers and real-time engines load fastest. If your model is destined for a website, an e-commerce product viewer, a three.js or Babylon.js scene, or an iOS or Android AR experience, glTF or GLB is almost always the right target. It carries PBR materials, textures, animations and a full scene hierarchy in a compact, GPU-friendly package.
Coming from a different mesh format? See how glTF compares to OBJ, FBX. Reduce glTF file size for the web
A .gltf file can reference external image and .bin files. If those files are not shipped alongside it, the model loads untextured. Export to GLB instead — it bundles geometry, materials and textures into one file that is safe to move and share.
GLB and glTF hold the same data. .gltf is JSON plus separate asset files; .glb packs everything into one binary. Use GLB for the web, AR and sharing; use .gltf when you want to inspect the JSON or swap textures. 3D CAD Converter exports either.
Detailed CAD geometry can produce heavy GLB files that load slowly in a browser. Enable Draco compression in the glTF settings to cut size by 80–90% with little visible loss. See the file-size guide
Blender, Sketchfab, Three.js, Babylon.js, Unreal Engine, Godot, Unity (via plugin), iOS AR Quick Look, Android SceneViewer, and all modern web 3D renderers.
Commonly converted from STEP or OBJ for web visualization and e-commerce, to GLB for a single self-contained file, or to OBJ for legacy renderers.
A .glb file is the binary form of glTF. It bundles the JSON scene, mesh geometry, PBR materials, textures and animations into a single self-contained file, which makes it the easiest 3D format to share and to load on the web, in AR and in game engines. A .gltf file holds the same data but may reference external .bin and image files.
They are the same Khronos format in two packagings. A .gltf file is JSON that can point to external geometry and texture files, so it ships as several files; a .glb file packs everything into one binary. Use GLB for the web, AR and easy sharing; use .gltf to inspect the JSON or swap textures separately. 3D CAD Converter exports both.
Open the STEP or OBJ file in 3D CAD Converter, choose glTF/GLB as the output, and convert — drop a folder to batch many parts. From the command line run cadconvert convert -i part.step -o part.glb or cadconvert convert -i model.obj -o model.glb. To shrink the result, enable Draco compression in the desktop glTF settings.
Yes. GLB files open in many free viewers, including the Windows 3D Viewer, the Khronos glTF Sample Viewer, the Babylon.js Sandbox and Google model-viewer in any browser. 3D CAD Converter previews glTF/GLB and converts it to OBJ, STL, FBX and more. You do not need Blender to view, share or convert a glTF file.