Kept
- Vertices and faces of every object in the file
- Shape, dimensions and orientation
- UV seams do not alter the silhouette
Runs locally · no upload
Convert OBJ to STL
Turn an OBJ mesh into a printable STL. The tool reads the geometry only: MTL files, textures and material names are not part of the result.
- Free preview
- Account to download
- 5 credits per file
- 60 free credits at signup
- See credits ↗
Drop a 3D file hereSTL, OBJ, PLY, GLB, glTF, 3MF or STEP · up to 100 MB · processed locallyYour file never leaves this browser.
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What changes in the conversion
Dropped
- MTL materials and textures
- Colours and shading information
- N-gons are triangulated
Common mistakes
- OBJ files that reference an MTL file still load, but materials are ignored.
- If the OBJ contains only curves or points, there is no surface to export.
- A mesh with flipped normals may look dark in some viewers; repair it before printing.
For 3D printing
- STL is the safest format for slicers; OBJ with MTL is useful for rendering, not for printing.
- Check for holes and non-manifold edges after conversion: OBJ does not guarantee a watertight mesh.
Drop the file — it is read locally, never uploaded.
Choose the options, then convert or compress.
Download the result and open it in your slicer or 3D software.
Frequently asked questions
Do I need to upload the MTL file too?+
No. This tool converts geometry only, so the MTL is ignored. If you need materials, keep the OBJ and use a renderer that reads MTL.
Does it fix a non-watertight mesh?+
No. It converts the surface as it is. Holes and flipped normals must be repaired in a mesh tool before slicing.
Is the STL binary or ASCII?+
The output is a binary STL, which is smaller and faster to load in slicers.
Need a model instead of a conversion?
Turn a photo, a drawing or a logo into a 3D model, then export it in the format you need.