Convert OBJ to STL
Convert OBJ files to STL in your browser. Free, no upload, no sign-up.
Convert OBJ files to STL directly in your browser. The converter parses the OBJ mesh, rebuilds it in memory and writes it out as STL, triangle for triangle. STL records shape and nothing else, so the textures, materials and separate objects (they are merged into one mesh) in the OBJ file do not come across. Neither format records which way is up, so the converter reads OBJ as Y-up and writes STL as Z-up, the convention the tools on each side use; the workspace has a switch if your file disagrees. Nothing is uploaded, there is no file size limit beyond your computer's memory, and the result downloads instantly. STL is accepted by every slicer and 3D printer, so it is the safest format to hand to anyone who needs to print your model.
How to convert OBJ to STL
- 1Drop your OBJ file
Drag a .obj file onto the box above or click to choose one. The companion .mtl file and textures are ignored. Geometry is imported completely.
- 2Check the preview
The model renders in 3D so you can confirm it loaded correctly. Dimensions, volume and triangle count are shown next to it; open edges are flagged if the mesh is not watertight.
- 3Download the STL
Adjust the export options if needed and click download. Colors, textures and materials are dropped because STL cannot store them. Multiple objects are merged into one triangle soup; units are not recorded, so make sure the model is already in millimeters.
What are OBJ files?
OBJ is a plain-text mesh format from Wavefront. It stores vertices, normals, UV texture coordinates and face definitions, and references materials through a companion .mtl file. It is human-readable and supported by virtually every 3D modelling application.
Commonly used by: Blender, Maya, ZBrush, game engines, photogrammetry tools
The companion .mtl file and textures are ignored. Geometry is imported completely.
What are STL files?
STL is the oldest and most widely supported 3D printing format. It stores nothing but a list of triangles, with no color, texture, unit or scale information. Every slicer and almost every 3D tool can read it, which is why it is still the default exchange format for printable models.
Commonly used by: 3D printer slicers (Cura, PrusaSlicer, Bambu Studio), CAD export, Thingiverse / Printables
STL is accepted by every slicer and 3D printer, so it is the safest format to hand to anyone who needs to print your model.
OBJ vs STL
| OBJ | STL | |
|---|---|---|
| Full name | Wavefront OBJ | Stereolithography |
| Encoding | Text | Text or binary |
| Geometry type | Triangle mesh | Triangle mesh |
| Colors | No | No |
| Textures | Yes | No |
| Materials | Yes | No |
| Stores units | No | No |
| Multiple objects | Yes | No |
| Typical use | Blender, Maya, ZBrush | 3D printer slicers (Cura, PrusaSlicer, Bambu Studio), CAD export, Thingiverse / Printables |