Free STL to GLB Converter
Lightning-fast STL to GLB conversion — 100% in your browser. Your files never leave your device. Free, no watermark, no sign-up.
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Supports GLB, GLTF, OBJ, STL, FBX, PLY
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STL vs GLB
See what transfers when converting between these two formats.
| Feature | STL | GLB |
|---|---|---|
| Geometry | ||
| Textures | ||
| Materials | ||
| Animation | ||
| Rigging |
All features supported by STL are preserved in GLB.
STL → GLB: format spec comparison
Hard facts side by side — what each format is, where it comes from and what it can hold.
| Spec | STLSource format | GLBTarget format |
|---|---|---|
| Developer | 3D Systems (Chuck Hull, SLA inventor) | Khronos Group |
| First released | 1987 | 2017 |
| Data model | Triangle soup, ASCII or binary | Binary container (single file) |
| Textures | None | Embedded, full PBR |
| Animation | None | Skeletal + morph targets |
| Typical size | Binary moderate; ASCII very large | Smallest (buffers compressed in one payload) |
| Openness | Open, de-facto standard | Royalty-free open standard |
| Primary use | 3D printing (FDM / SLA / SLS) | Web 3D, AR, AI generation output |
Why convert STL to GLB?
Showcase 3D-printing models on the web
STL files from Thingiverse, Printables, or your own slicer prep can be displayed in interactive web viewers by converting to GLB.
AR and WebXR experiences
Apple Quick Look, Google Scene Viewer, and WebXR sessions all expect GLB. Convert STL scans or prints before deploying to AR.
Game engine import
Unity and Unreal accept GLB natively via plug-ins. STL is supported but with no UVs or materials, importing as plain geometry.
Tips for STL → GLB
STL has no materials
STL carries only geometry. The converted GLB will have a plain default material — add your own in Blender or Three.js after conversion.
Binary STL converts faster
Binary STL is roughly 4x smaller than ASCII STL and parses much faster. If your STL is ASCII, consider re-exporting from your CAD tool as binary first.
Watertight meshes preferred
STL slicers demand manifold geometry; GLB viewers tolerate non-manifold meshes. Either way, watertight meshes convert cleaner and render correctly.
Add UVs in Blender if you need textures
STL has no UV coordinates. To texture the converted GLB, open it in Blender, unwrap UVs, apply a material, and re-export as GLB.
Common issues when converting STL to GLB
GLB looks uniform grey
Fix
STL has no material data. The converted GLB uses a default material. To add color, open the GLB in Blender, assign a material with a diffuse texture, and re-export.
File is huge after conversion
Fix
Decimate the mesh in Blender (try 50% ratio as a starting point) before converting. For web delivery, run the GLB through gltfpack or glTF-Transform to apply Draco or Meshopt compression.
Model scale is wrong
Fix
STL stores coordinates in source-file units. If your STL was exported from CAD in millimeters, the GLB inherits those values. Three.js and model-viewer typically default to meters — scale by 0.001 in the viewer or before conversion.