STL to GLB Converter

Drop an .stl file (binary or ASCII) and this tool reads its triangle mesh with three.js's STLLoader, computes shading normals, and re-exports the result as a binary .glb file you can drop into a web viewer, AR app or game engine. Everything runs locally; the model is never uploaded.

PrivateFreeWorks offline

Reviewed by Vincenzo Manto, Founder & Lead Developer · Last updated October 4, 2026

How it works

  1. 1

    Drop or select an .stl file (binary or ASCII).

  2. 2

    The tool reads the triangle mesh with three.js's STLLoader and computes normals for shading.

  3. 3

    The mesh is re-exported as a single binary .glb file.

  4. 4

    Preview the model and download the .glb.

A printer format meets the web

STL stores nothing but raw triangles - no color, materials or scene graph - which is all a 3D printer slicer needs. GLB adds materials, a scene hierarchy and compact binary packaging, making the same shape usable in web viewers, AR and game engines without re-modeling it.

Powered by three.js, right in the page

This tool uses three.js's STLLoader to parse the mesh and its GLTFExporter to write the GLB, loaded on demand via a dynamic import so the rest of the site stays fast for everyone else.

Frequently asked questions

Does this support both binary and ASCII STL?

Yes. three.js's STLLoader auto-detects the variant and parses either one the same way.

STL has no color or texture - what will the GLB look like?

STL only stores geometry, so the exported GLB gets a neutral gray material. You can recolor or retexture it afterwards in any 3D editor or viewer that supports GLB materials.

Why convert an STL (made for 3D printing) to GLB?

GLB lets you show the same model in a web page, AR preview or game engine without a 3D-printing slicer, and it compresses the triangle data more efficiently than STL's uncompressed, often duplicated vertices.

Is my model uploaded anywhere?

No. Parsing and conversion happen entirely in your browser using three.js; the file never leaves your device.

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