Convert OBJ to STL
Turn supported OBJ polygon geometry into a binary STL, with local preview and clear conversion warnings.
Supported input and output
Geometry-first OBJ input; binary STL output. Simple planar polygons are triangulated; positive and relative indices are supported.
Geometry without the material files
OBJ faces can refer to texture coordinates, normal vectors and material files. Here, supported planar polygons are triangulated and written as binary STL. Object labels and materials do not survive, and companion MTL or image files are never loaded. Coordinate values are retained, so confirm their intended unit in your slicer.
How to use this tool
- Choose an OBJ file containing polygon meshes.
- Inspect the triangulated geometry and loss warnings.
- Convert to STL, download it and set the intended import units.
Limitations to check
- STL discards materials, textures and object/group labels. Source winding determines generated face normals.
- Coordinates are unchanged and units remain unspecified. Binary STL uses 32-bit coordinates; precision loss is possible, and collapsed triangles are rejected.
- Non-planar/self-intersecting polygons, curves, lines, points and rational vertices are unsupported. This tool does not repair or boolean-union meshes.
File and processing limits
- OBJ input up to 25 MiB; 750,000 vertices, 250,000 triangles and 256 object/groups.
- At most 16,384 characters per line, 1.5 million lines and 128 vertices per polygon.
- Generated mesh output is limited to 64 MiB.
- 30 seconds per mesh job. Browser memory and device speed can impose lower practical limits.
Processing happens in this browser; your file and filename are not uploaded. Cancel, reset or replace the file to stop its worker. Downloads are generated locally.
Questions about this workflow
Why does the exported model have no texture?
This STL output stores triangle geometry only. A texture changes surface appearance, not mesh shape; its image details are not converted into raised or recessed geometry.