Convert OBJ to STL.
Convert an OBJ 3D model to STL — the standard format for 3D printing and slicers. Geometry preserved exactly.
OBJ to STL, ready for the slicer
OBJ is a common editing and interchange format — it can carry materials, UVs and texture references alongside the mesh. STL is what 3D-printing slicers like Cura, PrusaSlicer and Bambu Studio expect: just the geometry. Converting an OBJ you've modelled or downloaded to STL is the step that makes it printable.
Geometry only
STL keeps just the triangle mesh — any materials, colours or UV coordinates the OBJ carried are dropped, since a slicer works purely from the shape. Multi-part models are merged into a single mesh for a clean result.
Watch for non-manifold geometry
Before printing, make sure the mesh is watertight — holes, flipped normals or non-manifold edges can confuse a slicer. Most slicers and tools like Meshmixer or Blender can detect and repair these. Keep the original OBJ for editing if you'll keep refining the model.
How it works
- 01
Upload your OBJ
Drop a 3D model or pick one from your device. Private by default.
- 02
Convert with trimesh
trimesh reads the geometry and writes STL — vertices and faces preserved exactly, no paid API in the loop.
- 03
Download
Grab your STL.
Geometry preserved exactly — vertices & faces
Watertight meshes stay watertight
Private uploads, auto-deleted after 1 hour
No watermark, no signup to try
Free and open-source engine (trimesh)
OBJ to STL
This converts the 3D geometry from OBJ to STL. Vertices and faces carry over; support for colour, materials and textures depends on the target — STL keeps more scene data.
Common questions
Is it free?+
Yes — convert OBJ to STL free. No signup, no watermark, no daily cap.
Is my model private?+
Uploads go to a private bucket, are converted, and auto-delete after 1 hour. Files never touch a third-party converter.
Is the geometry changed?+
No — vertices and faces are preserved exactly. Multi-part scenes are merged into a single mesh for clean output.
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