free · in-browser · no upload

GLB to STL
Converter

Drop your GLB file. We'll convert it to STL right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .glb

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

1
Drop your file
Click the dropzone above or drag a GLB from your desktop. Files of any size, there's no upload, so there's no upload limit.
2
Convert in your browser
The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.
3
Download
Get your STL the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert GLB → STL

What this conversion is actually for

Your 3D printer slicer (Cura, PrusaSlicer, Bambu Studio, Slic3r, Simplify3D) wants STL. The .glb file you downloaded from Sketchfab, Thingiverse's newer GLB section, or extracted from a game asset pack won't import directly. glb-to-stl extracts the mesh geometry and emits a clean binary STL ready for slicing.

A real example

You downloaded a `dragon.glb` from a Sketchfab CC-BY-licensed model pack. PrusaSlicer doesn't open GLB. Convert to `dragon.stl` here, open in PrusaSlicer, scale to print bed, slice, print. Total round-trip: 90 seconds.

Troubleshooting

The STL came out smaller (fewer triangles) than I expected.

We currently extract only the first mesh primitive of the first mesh in the GLB's scene graph. Multi-mesh GLBs (e.g., a character with separate body+clothing meshes) only yield the body. To merge meshes, open the GLB in Blender → Object Mode → Select All → Ctrl-J (Join) → File → Export → glTF .glb, then re-run this converter.

The model appears tiny or huge in my slicer.

GLB convention is meters; STL convention is millimeters in most slicers. If your dragon is 1 unit tall in GLB, it'll be 1 mm tall in PrusaSlicer. Scale the STL up by 1000x in the slicer (right-click → Scale → 1000%) or scale in Blender before exporting.

Formats involved

About GLB and STL

GLB, glTF 2.0 Binary

GLB is the binary container for glTF 2.0 — the Khronos Group's web-native 3D format, often called "the JPEG of 3D." A single .glb file packs the model's JSON metadata (scene graph, materials, animations) and binary buffers (vertex positions, normals, UVs, indices, textures) into one self-contained download, ideal for streaming over HTTP. Universal support across the modern 3D stack: Three.js, Babylon.js, model-viewer (Google's `<model-viewer>` web component), Sketchfab, Facebook 3D posts, Microsoft 3D Viewer, Apple QuickLook (via USDZ conversion), Blender (import/export), Unreal Engine, Unity. Every WebXR/AR/VR pipeline reads GLB. Spec finalized in 2017 as glTF 2.0; binary chunk format kept stable since.

How to open

Drag-and-drop into https://gltf-viewer.donmccurdy.com or https://sandbox.babylonjs.com/. Blender opens .glb via File → Import → glTF 2.0. The `<model-viewer>` web component renders them on any webpage with `<model-viewer src="model.glb">`. Microsoft 3D Viewer (Windows) and macOS Preview (with USDZ Tools) handle GLB natively.

Full GLB format guide →

STL, Stereolithography

STL is the lingua franca of 3D printing, every slicer (PrusaSlicer, Bambu Studio, Cura, Simplify3D) reads it. Files are unstructured triangle soup: no scene graph, no materials, no scale info, just vertices and triangles. The format is ancient (1987) and primitive but its simplicity is exactly why it's universal. Two variants: ASCII (human-readable, big) and binary (compact, what most software produces).

How to open

Every 3D printing slicer, every CAD/3D tool (Blender, FreeCAD, Fusion 360, SolidWorks, Tinkercad). Free viewers: ViewSTL, MeshLab, online STL viewers.

Full STL format guide →

Related tools

Convert other files to STL

Convert your GLB to other formats

GLB → OBJ

FAQ

Common questions

Is this GLB → STL converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert GLB to STL?

3D model delivery for the web (AR product viewers, WebXR scenes, embedded 3D widgets) and modern game-engine workflows. 3D printing, feed an STL into your slicer to get G-code. The most common reason to convert is compatibility, STL works in places where GLB doesn't, or vice versa.

How do I open a GLB file in the first place?

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.

GLB to STLConverter