Convert STEP to GLB
Free STEP to GLB converter that runs in your browser. See real dimensions before you download.
Why convert STEP to GLB?
STEP to GLB takes an engineering model and makes it viewable on a web page, in an AR session or inside a game engine. CAD files are not displayable in a browser, but GLB is. The conversion tessellates the exact surfaces with OpenCascade at the quality you choose, then writes the result as a single binary glTF. Assembly parts become separate meshes, so a viewer can colour or hide components individually. Colours in the STEP are kept as material colours. STEP uses millimetres in most cases, while glTF is defined in metres, so MeshShift scales the model so that a 100 mm part is 0.1 in the GLB and shows at the right size in AR. The up axis is changed from Z-up to Y-up.
How to convert STEP to GLB
- Drop your STEP file onto the converter — it opens in your browser, nothing is uploaded.
- Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
- Choose GLB as the output and click Convert. Several files download as one ZIP.
What carries over from STEP to GLB
| STEP | GLB | Result | |
|---|---|---|---|
| Colour / materials | Yes | Yes | Kept |
| Textures | No | Yes | — |
| Units stored in file | Yes | Yes | Written as mm → metres |
| Separate parts | Yes | Yes | Kept |
| Usual up axis | Z | Y | Rotated (switchable) |
What changes
- Exact CAD surfaces become triangle meshes.
- Millimetres are converted to metres, and Z-up to Y-up.
- Assembly parts stay as separate meshes; the full CAD feature tree is not kept.
- Product metadata and parametric information are not stored in GLB.
Tips
- For web use, choose Normal or Draft to keep the GLB small; Fine for close-up AR.
- Check part colours in the viewer; STEP colours are kept if they were defined.
- Hide internal fasteners and tiny parts in CAD before export to lower the triangle count.
- Large assemblies may be heavy for mobile; split them or reduce quality.
About STEP files
STEP, formally ISO 10303 and known as the Standard for the Exchange of Product model data, has been developed since the 1980s and is the main neutral format for moving CAD models between companies and systems. The usual application protocols are AP203 and AP214 for geometry and assemblies, and AP242 for modern product and manufacturing information. A .step or .stp file is plain text written in the EXPRESS-based Part 21 syntax. Unlike STL, it does not store triangles: it stores boundary representation (B-rep) geometry, meaning exact planes, cylinders, splines and NURBS surfaces joined by edges and faces into solids. That keeps holes perfectly round and dimensions precise, and allows the receiving CAD to keep editing faces. Files can contain assemblies, product structure, colours and units.
About GLB files
GLB is the binary container for glTF 2.0, the format the Khronos Group describes as the JPEG of 3D. One .glb file bundles a JSON scene description, binary mesh buffers and embedded images, so nothing can go missing in transit. The format was designed for efficient delivery and loading on the web, and it is now used by Three.js, Babylon.js, model-viewer, Google Search 3D results, Meta platforms, Unity and Unreal importers, and many marketplaces such as Sketchfab. glTF defines a physically based metallic-roughness material model, a node hierarchy, cameras, skins and animations. Coordinates are in metres with +Y up and a right-handed system. It is excellent for display and game assets, but it is a presentation format rather than a manufacturing one, so print workflows usually convert it first.
3D printing notes
Most slicers cannot read STEP, though some, like PrusaSlicer, will import it and mesh it internally, so the usual step is exporting STL or 3MF from your CAD program. Tessellation quality decides how smooth the printed curves look: too coarse and cylinders become visible facets, too fine and files grow huge. MeshShift reads STEP and STP using OpenCascade in the browser and lets you pick draft, normal or fine tessellation. When it writes STEP, the result is a faceted B-rep: a solid made of flat triangular faces, not a parametric CAD model, so it will not give you editable holes or fillets. Use it to exchange a mesh as a solid, not to recover design intent.
Frequently asked questions
Does the GLB keep the assembly structure?
Parts are kept as separate meshes so you can treat them individually in a viewer. The full CAD tree with features and constraints is not stored.
How big will the GLB be?
It depends on tessellation quality and the number of curved faces. Draft and Normal produce much smaller files than Fine. Reduce quality if the model is for a web page.
Is this STEP to GLB converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your STEP file is never uploaded to a server. There is no sign-up, no watermark and no daily limit; very large files are limited only by your device's memory.