OBJ to STL Converter
Drop a Wavefront OBJ from Blender, Maya, or ZBrush — get a slicer-ready binary STL. Materials are stripped (STL doesn't carry them), geometry is preserved exactly.
Drop your OBJ file here
Converts to .stl — stays on your device
Why convert OBJ to STL?
- Sending a Blender sculpt to Cura, PrusaSlicer, or Bambu Studio for FDM or resin printing.
- Converting a ZBrush ZTL→OBJ export into the STL form your slicer wants.
- Producing a printable STL from a Maya or 3ds Max asset that started as an OBJ.
- Bringing a scanned mesh that traveled through OBJ-using DCC tools into a print pipeline.
- Generating an STL for Bambu Studio or OrcaSlicer from an OBJ asset shared by an artist.
- Creating jewelry, prototype, or model-train STLs from CAD-tool OBJ exports.
How our converter works
Your OBJ is parsed by three.js's OBJLoader into a Group of Meshes — vertices, faces, and normals are extracted into BufferGeometries. We feed the entire scene to three.js's STLExporter in binary mode, which produces a compact STL with per-face normals (auto-computed if the source didn't supply them). Multiple meshes in the OBJ are flattened into a single triangle list, which is what slicers expect. Conversion runs entirely in your browser.
Frequently asked questions
Will the STL open in Cura/PrusaSlicer/Bambu?
Yes. The exporter writes binary STL, which every slicer accepts (and prefers — it's about 5x smaller than ASCII STL). Drop the .stl directly onto the slicer or use File → Open.
What happens to materials and colors?
They're dropped — STL has no material concept, so the output is pure geometry. If your OBJ referenced a .mtl sidecar, that information is lost. For colored 3D printing (e.g. Bambu's AMS multi-material), you'd need a different format like 3MF (on the roadmap).
Is the output binary or ASCII STL?
Binary, which is the slicer-preferred format. Binary STL is ~5x smaller than ASCII for the same geometry, parses faster, and every slicer supports it.
Will multi-mesh OBJs work?
Yes. Multiple meshes in the OBJ are merged into a single triangle list in the STL output. If you need each part as a separate STL, split them in your DCC tool first and convert each.
Are my files uploaded?
No. The conversion runs as JavaScript on this page using three.js — your model never leaves your device.
About the OBJ format
OBJ is the Wavefront ASCII text format that became the default interchange between 3D content tools — Blender, Maya, ZBrush, 3ds Max, and most CAD systems can read and write it. It supports vertices, normals, UVs, faces, and material references (via a separate .mtl file). STL (Stereolithography) is the format every 3D printer slicer reads — a stripped-down triangle list with surface normals, no materials, designed for fabrication rather than editing. Converting OBJ→STL is the standard final step in a 3D-printing workflow: sculpt or model in your DCC tool of choice, then export STL for the slicer that drives the printer. The conversion is lossy in the materials sense (those data layers don't survive), but lossless in geometry.