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STEP to OBJ converter

Drop your .step / .stp file — we convert it to .obj right in your browser. Files never leave your computer.

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Drop your STEP file here
Accepts .step / .stp · converts to .obj

STEP vs OBJ— what's the difference?

STEP.step / .stp

ISO 10303 boundary-representation CAD format — the industry standard for exchanging precise, parametric solid models between engineering tools.

Strengths
  • Exact curved surfaces (NURBS / B-rep) — no tessellation loss
  • Assembly hierarchy, part names and metadata preserved
  • Supported by every major MCAD tool (SolidWorks, Inventor, Fusion, Creo, NX…)
  • Open, vendor-neutral ISO standard
Limitations
  • Not directly consumable by 3D printers or game engines
  • Files are larger and slower to open than mesh formats
  • Requires a CAD kernel to read — no native browser support
Typical use: Engineering CAD exchange, mechanical design, supplier handoff
OBJ.obj

Human-readable Wavefront mesh format — ubiquitous in 3D graphics, game art, and asset pipelines. Pairs with a .mtl material file.

Strengths
  • Supported by virtually every 3D tool (Blender, Maya, 3ds Max, Unity, Unreal…)
  • Plain-text, easy to diff and hand-edit
  • Keeps UV coordinates and vertex normals, unlike STL
  • Material references via companion .mtl file
Limitations
  • Text format — larger on disk than binary meshes
  • No scene hierarchy, no animation, no skeletons
  • Materials live in a separate file; easy to lose
Typical use: 3D art pipelines, DCC handoff, asset archives

How to convert STEP to OBJ

  1. 1
    Drop a .step or .stp file on the page. The CAD kernel runs in your browser via WebAssembly — nothing uploaded.
  2. 2
    Preview the tessellated model in 3D. Confirm the hierarchy via the Scene Tree sidebar.
  3. 3
    Click Download .OBJ. Pull the file into Blender, Maya, 3ds Max, Unity, or Unreal.

FAQ

Why go STEP → OBJ instead of STEP → FBX or GLB?

OBJ is the lowest-common-denominator mesh format — every DCC and renderer reads it. If you're shipping CAD to a 3D artist who doesn't use a CAD tool, OBJ is the safest format. For web / AR, prefer GLB.

Is my STEP file uploaded anywhere?

No — everything runs in-browser using occt-import-js (OpenCascade WASM) and Three.js' OBJ exporter.

Will the OBJ keep part / assembly names?

OBJ has 'o' (object) groups but no real hierarchy. Part names from the STEP appear as groups; nested assemblies are flattened.

Will the OBJ have UVs or a .mtl file?

No UVs (STEP has none to start with — it's B-rep) and no .mtl (no materials in STEP either). Assign in Blender / your DCC post-import.

What about curved faces?

STEP's exact NURBS surfaces get tessellated into triangles during export. This is intrinsic to moving from B-rep to mesh, not a limitation of this tool.

Related converters

STEP → STLSTEP → GLBSTL → OBJOBJ → STL