Free converter

Convert STL to glTF for 3D pipelines.

Drop an .stl below and download it as glTF 2.0 JSON — the standard format of web 3D. The conversion runs in your browser and nothing is uploaded. Prefer a single compact binary? The STL to GLB converter writes a .glb instead.

Drop your STL file here
or click to browse — converted in your browser, never uploaded
.stl

Converted locally · never uploaded · no signup

Why this tool

Free, private, in the browser.

Print file to web standard

STL is for slicers; glTF is what browsers, engines and AR runtimes load natively. This converts one to the other in seconds.

Indexed, efficient geometry

STL repeats vertices per triangle; glTF stores them indexed, so the output is typically much smaller than the source.

Converted locally

Parsed and exported with three.js in your browser — no upload, no account, no waiting.

How it works

Three steps, no setup.

01
Drop your STL

Drag the .stl in and check the live preview.

02
Convert to glTF

The mesh is re-encoded as glTF 2.0 JSON with embedded buffers.

03
Use it on the web

Load the .gltf in three.js, Babylon, <model-viewer> or your engine of choice.

Why take an STL into glTF?

STL ends at the printer — browsers and engines don't load it. If you want to show a printable design on a product page or portfolio, feed it to a game engine, or run it through glTF-based tooling, converting to glTF gives you a standards-compliant asset every modern 3D stack accepts. For pure deployment the binary GLB variant is smaller; the JSON .gltf shines when tooling wants to read the file.

Materials after conversion

STL carries no color or material data, so the glTF is written with a neutral standard material. The geometry and computed normals convert exactly — ideal for assigning materials in a web viewer's environment, in Blender, or with Sculpty's texturing studio, which generates PBR textures from a text prompt.

Questions

Answered, plainly.

Is the STL to glTF converter free?+

Yes — free and unlimited, with no signup and no watermark.

Does the conversion upload my file?+

No. The STL converts to glTF entirely in your browser and downloads straight from memory.

Should I pick glTF or GLB output?+

Same data, different container. GLB is smaller and best for shipping; .gltf is JSON and best when you or your tooling need to read the file. Both converters are free here.

Will the glTF have materials?+

A neutral default material, since STL carries none. Texture the model afterwards in your tool of choice.

More free tools
STL to GLB ConverterglTF to STL ConverterglTF to GLB ConverterAll free tools →
Sculpty studio

Don't have a model yet? Generate one.

Type a prompt, get a textured 3D model in about a minute — then download it as GLB, STL, OBJ, FBX or USDZ.

Generate a model from text →