STL → GLB · FREE · NO UPLOAD
STL to GLB Converter — Take a Print File to the Web
Turn a .stl into a web-ready .glb for online viewers, AR pipelines and game engines — in the browser, nothing uploaded.
Putting a print file on a product page
A printable STL is a triangle list. A product page wants a file a browser can draw. GLB — binary glTF — is that file. This page turns the print mesh into a web mesh you can embed with <model-viewer> or upload to a platform that accepts glTF. No desktop app is required for the conversion itself.
- Start with the STL you already slice. Drop it on the converter above. The preview is the geometry that will go into the GLB: same triangles, wrapped in a glTF scene with a neutral gray material because STL has no color to carry over. Download the GLB when the preview looks right.
- Embed that GLB with <model-viewer> on the product page, or upload it to a host that takes glTF. Either path gets a rotatable 3D preview in the browser, which an STL usually will not. The file is typically smaller than the binary STL as well, because glTF stores an indexed mesh instead of repeating every vertex. What you will not get from this conversion is an authored look: no metal, no logo texture, no painted plastic. The exporter assigns a plain PBR material so the model renders; replacing that material is a separate job.
- When materials must be authored, take a Blender round-trip instead of stopping at this download. Open the mesh in Blender, assign materials there, then use File → Export → glTF 2.0 (.glb/.gltf) to write a GLB that actually carries those materials. That is the right path for a finished look on a storefront. This page is the right path when you need a faithful shape on the page today and you do not want to open a 3D editor for a gray preview.
Watch units if the on-page viewer looks tiny or huge. Slicers assume STL numbers are millimeters. glTF's spec unit is meters. A 50 mm part stored as 50 in the STL becomes 50 meters in a strict glTF reading, or a 0.05 m part becomes 0.05 mm if you later convert back for print. Many web viewers ignore the unit and just fit the camera to the bounding box, so the product page still looks fine. If you also print from the same numbers, keep the two conventions straight.
Use this converter for the fast STL-to-GLB hop onto a product page. Use Blender's File → Export → glTF 2.0 when the page needs materials you have to paint. The reverse trip — a web or AI GLB back to a printable STL — is the GLB to STL converter.
Typical pipelines that start here
- Product page 3D viewer — <model-viewer> and Three.js load GLB natively; showing a printable part on your site starts with this conversion.
- Sharing a preview — a GLB opens on any phone from the browser; an STL usually doesn't.
- Game engines & XR — Unity, Unreal, Godot and WebXR toolchains import glTF cleanly.
- iOS AR — convert the GLB onward to USDZ with Reality Converter for Quick Look.
The reverse direction — printing a web or AI model — is the GLB to STL converter.
FAQ
Is my STL uploaded during conversion?+
No. The STL is parsed locally, wrapped in a glTF scene and re-encoded as a binary GLB — all with JavaScript in this tab. No upload endpoint, works offline once loaded.
Why convert STL to GLB at all?+
GLB is the format of the 3D web: model viewers on product pages, AR Quick Look via conversion pipelines, Three.js/Babylon scenes, Sketchfab-style embeds, game engines. STL is print-oriented and has no place in those pipelines — a GLB drops straight in.
Does the GLB get a material?+
Yes — STL carries no color, so the exporter assigns a neutral gray PBR material to make the model render correctly in viewers. You can retexture it in Blender or your engine; the geometry is what matters here and it is preserved exactly.
Is GLB smaller than STL?+
Usually, yes. Binary STL spends 50 bytes per triangle with every vertex repeated; glTF stores an indexed mesh, so shared vertices are stored once. Typical meshes shrink 30-60% — before any compression like Draco (which this tool does not apply, keeping maximum compatibility).
Will the model show up in AR?+
GLB is the Android/WebXR side of AR. iOS Quick Look wants USDZ — convert the GLB to USDZ with Apple's Reality Converter if you need iPhone AR. This page gets you the standards-compliant GLB that every other pipeline starts from.