OBJ to STL converter
Convert OBJ to STL free online to prepare 3D models for printing. Works with Cura, PrusaSlicer, and every major slicer. No signup, files deleted in 1 hour.
Drop a file to convert here
or click to browse
About Stereolithography
Common Use Cases
- Preparing 3D models for slicing and printing
- Exporting clean meshes for CNC and prototyping
- Submitting models to 3D print services like Shapeways
OBJ is great for editing and rendering, but 3D printers speak STL. Every slicer, every print service, and every FDM or resin printer expects STL input. Converting your OBJ to STL strips out materials and textures and produces the clean triangle mesh that slicers need to generate tool paths.
OBJ carries materials, textures, and named groups that slicers cannot use; STL distills the model down to pure triangle geometry, which is exactly what 3D printers require.
Why Convert OBJ to STL?
Print on any 3D printer
STL is accepted by every FDM, SLA, SLS, and MSLA printer on the market. Whether you use a Prusa, Bambu Lab, Creality, Formlabs, or industrial machine, STL is the expected input.
Compatible with every slicer
Cura, PrusaSlicer, Bambu Studio, OrcaSlicer, Simplify3D, and every other slicer imports STL natively. No plugins, no extra steps.
Upload to 3D print services
Online print services like Shapeways, Sculpteo, and i.materialise require STL uploads. Converting your OBJ first ensures a smooth submission without format rejection errors.
Smaller file size for sharing
Binary STL files are compact because they store only vertex coordinates and face normals. Stripping materials and texture data from OBJ typically reduces file size significantly.
When to use each
Use OBJ when...
- Editing in Blender, Maya, or 3ds Max
- You need materials, textures, and UV maps
- Collaborating with other 3D artists
- Rendering with V-Ray, Arnold, or Cycles
- Organizing scenes with named object groups
Use STL when...
- Sending to a 3D printer or slicer
- You only need the triangle mesh geometry
- Uploading to Shapeways or other print services
- Prototyping and manufacturing workflows
- Archiving the printable version of a model
Common use cases
- Preparing 3D models for slicing and printing
- Exporting clean meshes for CNC and prototyping
- Submitting models to 3D print services like Shapeways
How to use
- Upload your OBJ file. Drag and drop a .obj file onto the upload area, or click to browse. Files up to 500 MB are supported.
- Run the conversion. Click Convert File. Materials and textures are stripped, quads are triangulated, and the mesh is written as a clean STL ready for slicing.
- Download your STL. Save the .stl file and open it in your slicer of choice. Uploaded files are deleted from our servers within 1 hour.
Frequently asked questions
- Are materials and textures preserved?
- No. STL only stores triangle geometry. Materials, textures, UV maps, and named groups from the OBJ are discarded during conversion. If you need color, consider 3MF instead.
- Does the converter handle quads and n-gons?
- Yes. Any non-triangle faces in your OBJ are automatically triangulated during conversion, since STL only supports triangles.
- Will my slicer accept the output?
- Yes. The output is a standard binary STL file that works with Cura, PrusaSlicer, Bambu Studio, OrcaSlicer, Simplify3D, and every other slicer.
- Is converting OBJ to STL free?
- Yes. Free with no signup. Anonymous users get a daily allowance, registered accounts get higher limits, and Premium or Lifetime members get unlimited conversions.
- What is the maximum file size?
- The maximum file size is 500 MB per conversion.