# GLB to STL Converter

> Print models from AI generators, Sketchfab or the web: GLB to STL with the size converted from metres to millimetres and the model standing upright on the plate.

Page: https://printpal.io/convert/glb-to-stl
Updated: 2026-11-12
Use it: open https://printpal.io/convert/glb-to-stl in a browser and drop a file. Free, no account, files are processed locally and never uploaded.

AI 3D generators and web tools hand out GLB; slicers want STL. The converter reads the GLB (including Draco and Meshopt compressed ones), turns glTF's metres into millimetres and its Y up into Z up, and merges every mesh into one STL. A 0.12 m figure becomes a 120 mm STL, standing on the plate.

Textures, materials and animation are dropped, because STL stores only shape. AI models in particular are often not watertight; check the result in the [STL viewer](https://printpal.io/tools/stl-viewer) and run [Mesh Repair](https://printpal.io/tools/mesh-repair) if it reports open edges.

## How to convert GLB to STL

1. **Drop your GLB files.** Drop .glb files, including Draco, Meshopt and KTX2 compressed ones.
2. **Check the preview.** The model appears at the size and orientation it will have. Fix the file units, up axis or size under Size, units and orientation if needed.
3. **Choose STL options.** Binary STL by default (smallest, read everywhere). Tick ASCII only if an old tool asks for text STL.
4. **Convert and download.** One file downloads straight away. A batch gives a download per file and one .zip of all of them.

## What carries over

| | Result |
|---|---|
| Geometry | Every triangle is kept at full precision. |
| Color | Dropped: STL cannot store color. |
| Units | Converted from metres to millimetres, so it keeps its real size. A 0.05 m part comes out 50 mm. |
| Orientation | Turned from Y up to Z up, so it stands on the plate in a slicer. |
| Objects | Merged into one surface: STL has no objects. |
| Animation | Dropped: the model is written in its rest pose. |

## GLB at a glance (glTF 2.0 binary)

glTF 2.0 is the Khronos Group's "JPEG of 3D", and GLB is its single-file binary form. It is what AI 3D generators, Sketchfab downloads and web apps hand out, and it is the only common format whose units (metres) and axes (Y up) are fixed by the spec.

- **Stores:** Meshes, PBR materials, textures, animation and scenes in one binary file
- **Color:** Full: textures, base colors and vertex colors
- **Units:** Metres, fixed by the glTF spec
- **Up axis:** Y, fixed by the spec
- **File size:** Compact; Draco or Meshopt compression shrinks meshes 5 to 10 times
- **Opens in:** Web viewers, Blender, Windows, Android Scene Viewer, Godot, Unity and Unreal importers

## STL at a glance (Stereolithography (Standard Triangle Language))

Created by 3D Systems in 1987 for the first stereolithography printers, STL is still the format every slicer and print service accepts. It describes a surface as a list of independent triangles, with no shared vertices, units, colors or scene structure.

- **Stores:** Loose triangles: three corners and a normal each, binary or ASCII
- **Color:** None in the standard
- **Units:** None written; slicers assume millimetres
- **Up axis:** Z, the slicer convention
- **File size:** 50 bytes per triangle in binary, about 5 times that as ASCII
- **Opens in:** Every slicer, CAD tool and 3D app

## Tips

- **Arbitrary size** AI generators often export a model a metre or two across. Scale it in the converter (set the height in mm) or in the slicer.
- **Keep the color** For a multi-color printer, use the [AMS converter](https://printpal.io/tools/ams-converter) instead: it turns textures into filament colors.
- **Animated GLB** The STL is taken from the rest pose.

## FAQ

### Why is my STL from GLB so big or so small?

GLB is in metres. The converter converts to millimetres, so the STL has the size the GLB claimed. Many AI models claim an arbitrary size; set a height in mm under Size, units and orientation.

### Does GLB to STL keep textures?

No. STL stores geometry only. Use 3MF with the AMS converter for filament colors.

### Can it read Draco-compressed GLB?

Yes. Draco, Meshopt and KTX2 textures are all supported.

### Is the converter free? Are there limits?

Free, with no sign-up, watermark or file count limit. Batches and files of a few hundred MB work on most laptops; the only limit is your device's memory.

### Are my files uploaded?

No. Files are read and written by JavaScript and WebAssembly in your browser and never sent to PrintPal. The STEP and IGES reader is the only extra download, once, from a public CDN.

## Related

- [STL to OBJ Converter](https://printpal.io/convert/stl-to-obj)
- [STL to 3MF Converter](https://printpal.io/convert/stl-to-3mf)
- [STL to GLB Converter](https://printpal.io/convert/stl-to-glb)
- [GLB to OBJ Converter](https://printpal.io/convert/glb-to-obj)
- [GLB to glTF Converter](https://printpal.io/convert/glb-to-gltf)
- [STL to PLY Converter](https://printpal.io/convert/stl-to-ply)
- [GLB to 3MF Converter](https://printpal.io/convert/glb-to-3mf)
- [GLB to USDZ Converter](https://printpal.io/convert/glb-to-usdz)
- [3D model viewer](https://printpal.io/tools/3d-model-viewer)
- [3D model converter](https://printpal.io/tools/3d-model-converter)
- [Mesh Repair](https://printpal.io/tools/mesh-repair)
- PrintPal for LLMs: https://printpal.io/llms.txt