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3DAI
Free · runs in your browser · no signup

Convert STL to GLB in Your Browser

STL is how 3D printing files are shared, but web viewers, AR on phones, game engines and online stores load GLB. This tool turns a print file into a single .glb with proper normals, a colour you choose and a sensible real-world size, all on your own device.

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How to use it

  1. 1

    Add your .stl

    Drop a binary or ASCII STL onto the box, or click to pick one. Up to 100 MB.

  2. 2

    Choose a look

    STL carries no colour, so pick one. Smooth shading rounds off curved surfaces while keeping sharp edges; flat shows every facet.

  3. 3

    Check size and axis

    Millimetres to metres is selected, so a 120 mm print shows up 12 cm tall in AR. Z-up to Y-up stands it upright in glTF viewers.

  4. 4

    Download the GLB

    One .glb file with the mesh and material inside. Open it in a web viewer, Blender, Unity, Unreal or an AR app.

What to know before you convert

  • An STL has no colours, textures or UV coordinates, so the GLB gets one plain material in the colour you pick. Painting or texturing has to happen in a 3D editor afterwards.
  • Duplicate corner points are welded and normals are rebuilt, which makes the GLB much smaller than the STL in most cases. The triangle count stays the same.
  • All shells in the STL become one mesh. STL does not record separate parts, so they cannot be split back out.
  • glTF is measured in metres. If your STL was not modelled in millimetres, pick the matching scale or the model will look too big or too small in AR.
  • The output is plain glTF 2.0 with no Draco compression, so every viewer can read it. Very dense scans may still need decimating for the web.

Don't have a model?

Create one with AI from a photo, a sentence or a sketch. The generators use credits; this converter is free and stays in your browser.

Image to 3D →Turn one photo into a textured 3D model.Text to 3D →Describe an object and get a GLB.Sketch to STL →Draw it, get a printable model.

Frequently Asked Questions

STL files store triangle geometry only. There is no colour or texture in the file to carry over, so the converter applies the single colour you choose. To get multiple colours, paint or texture the model in Blender and export GLB from there.
glTF uses metres. With the default millimetres-to-metres scale, an STL that is 150 units tall becomes 0.15 m, which is how it appears in AR view. If the STL was made in inches or centimetres, choose that scale instead.
Printing tools treat Z as up, while glTF treats Y as up. Keep the Z-up to Y-up option on and the model is rotated so it stands the same way it stood on the build plate.
Smooth suits organic shapes and scans: faces that meet at less than 30 degrees blend together, sharper edges stay crisp. Flat shows every triangle, which looks right for low-poly and mechanical parts. Only the normals change; the geometry is identical.
Yes. GLB is the format used by the model-viewer web component, Shopify 3D media, Facebook 3D posts and most WebGL viewers. For iPhone Quick Look you would still need a USDZ copy.
No. The page reads the file and converts it inside your browser with the open-source three.js library. Nothing is sent to our servers, there is no account, and no credits are used. Closing the tab discards everything.