Free online STP to GLB converter

Web viewers, AR tools, and game engines commonly accept GLB but cannot open STEP CAD data directly. Conversion turns the precise CAD surfaces into a triangle mesh that real-time 3D software can render.

What STP files contain

STP and STEP files use the ISO 10303 standard for exchanging product-model data between CAD systems. The extensions .stp and .step normally refer to the same format.

Mechanical CAD tools including SOLIDWORKS, CATIA, Siemens NX, PTC Creo, Autodesk Inventor, Fusion, Onshape, and FreeCAD use STEP for transferring solids, surfaces, assemblies, names, colors, and some product metadata. STEP geometry is generally represented as mathematically precise boundary-representation surfaces and solids, not as the triangles required by graphics applications.

A STEP file can transfer usable geometry, but it usually does not preserve a model's original parametric feature history, sketches, constraints, or native CAD-editing structure.

What GLB files contain

GLB is the binary container form of glTF 2.0. One .glb file can package meshes, scene hierarchy, materials, textures, cameras, animations, and other glTF resources without the separate files used by a typical .gltf delivery.

GLB is widely supported in browser-based 3D viewers, Three.js, Babylon.js, Unity, Unreal Engine import workflows, and product-visualization and AR pipelines. Its single-file structure simplifies upload and distribution.

GLB meshes approximate CAD surfaces with triangles. A converted GLB is appropriate for visualization and interaction, but not for machining, tolerance analysis, or dimensionally authoritative CAD work.

Convert the file

1. Open the STP to GLB converter on 101convert.com.
2. Upload the .stp or .step file and select GLB as the output format.
3. Run the conversion, then download the resulting .glb file.
4. Open the GLB in the intended viewer or engine and check scale, part visibility, colors, and curved surfaces.

This route converts the file for free without installing software. Conversion includes tessellation, so the generated GLB contains a mesh rather than editable CAD solids.

Desktop conversion options

For models requiring controlled tessellation or inspection before export, use a CAD application that imports STEP and exports glTF/GLB. CAD Exchanger Lab supports STEP import and glTF export; open the model through File → Open, inspect the assembly structure, configure available tessellation settings, then use File → Export to create a glTF binary/GLB output.

Blender does not include reliable native STEP import in its standard installation. STEP import normally depends on a third-party add-on or an intermediate mesh export from another CAD tool, so it is best used for material editing, mesh cleanup, and final GLB export rather than as the primary STEP importer. Export from Blender with File → Export → glTF 2.0 and select the GLB format.

Quality and compatibility limits

Tessellation quality controls the trade-off between appearance and file size. A coarse mesh makes cylinders, holes, fillets, and curved surfaces visibly faceted; an excessively fine mesh increases triangle count, memory use, download size, and rendering time. Start with moderate quality and increase it only where close-up curved details require it.

Assembly hierarchy and part placement often transfer, but CAD-specific metadata, PMI, layers, exact surface definitions, and parametric information may be omitted. Check that all components are present and correctly positioned after export.

STEP colors and appearances do not map exactly to glTF's physically based material model. Metallic, roughness, transparency, textures, decals, and double-sided rendering may need adjustment in the target application or in Blender.

glTF does not impose one universal physical-unit convention. Confirm scale by measuring a known feature after import, especially when the source CAD model uses millimetres and the target scene expects metres. Also check the target application's practical limits for triangle count, texture dimensions, node count, and file size.