OBJ to STL Converter

OBJ to STL Converter

Convert Wavefront OBJ to STL for 3D printing. Supports both ASCII and binary STL output with watertight mesh generation. Compatible with Cura, PrusaSlicer, Bambu Studio, and all major slicing software. No software installation required.

Drag & drop your OBJ file here

or click to browse (Max 50MB for free users)

Supported: .obj files only

Why Convert OBJ to STL?

OBJ is the universal 3D format. STL is the universal 3D printing format. Convert your models for slicing and physical fabrication.

3D Printing Ready

STL is the standard format for every 3D printer slicer. Convert your OBJ models to STL for direct slicing in Cura, PrusaSlicer, Bambu Studio, or Simplify3D.

Binary or ASCII Output

Choose binary STL for compact file sizes (up to 10x smaller) or ASCII STL for human-readable debugging. Both produce identical printed results.

Watertight Conversion

Our converter produces manifold, watertight STL meshes with correct face normals. Ready for FDM, SLA, and SLS 3D printing without additional mesh repair.

Universal Slicer Support

Output compatible with every major slicer, Cura, PrusaSlicer, Bambu Studio, Simplify3D, Lychee, Chitubox, and all resin and FDM slicing software.

About OBJ to STL Conversion

Why convert OBJ to STL?

OBJ is a rich format supporting colors, textures, materials, and multi-object scenes. Excellent for modeling and rendering. STL (Stereolithography) is the universal 3D printing format, a simple list of triangles with no colors, textures, or materials. Converting OBJ to STL strips away visual data and produces a clean, watertight triangle mesh that every 3D printer slicer can process. This is the essential step between digital model and physical object.

What is preserved during conversion?

Mesh geometry (vertices and faces) and vertex normals are preserved in the STL output. Colors, textures, UV coordinates, and material data are not preserved. STL is a geometry-only format. The converter ensures the output is manifold and watertight with consistent face normals. For models with non-manifold geometry, use our Mesh Repair tool before converting to STL for best print results.

How to use the converted STL file

The STL file is ready for direct import into Cura, PrusaSlicer, Bambu Studio, Simplify3D, Lychee Slicer, Chitubox, or any 3D printing slicer. Scale your model in the slicer to match desired print dimensions, select your material (PLA, ABS, PETG, resin), configure layer height and infill, slice, and print.

How to Convert OBJ to STL

Three steps to convert your OBJ models into 3D-printable STL files.

1

Upload Your OBJ File

Drag and drop your .obj file. Choose binary STL (compact) or ASCII STL (human-readable). Free tier: up to 50MB with 3 daily conversions.

2

Convert to STL

Our cloud engine triangulates OBJ faces, recalculates face normals, and writes watertight binary or ASCII STL output. Ready for any 3D printer.

3

Slice & Print

Download your STL and import into Cura, PrusaSlicer, or Bambu Studio. Scale, configure print settings, slice, and print. Files auto-delete within 1 hour.

Related Converters

Preparing models for 3D printing? These converters complete your workflow.

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FAQ

Frequently Asked Questions

OBJ supports colors, textures, and materials but 3D printer slicers require the simpler STL format. Converting OBJ to STL extracts the raw triangle mesh and writes it as a watertight file that Cura, PrusaSlicer, Bambu Studio, and every 3D printer can understand. Think of OBJ as the editable source file and STL as the printable output file.
Yes. You can convert up to 3 files per day for free with files up to 50MB each. For unlimited conversions, 500MB files, and batch processing, upgrade to Pro.
Binary STL is 5-10x smaller and faster to parse the standard choice for 3D printing. ASCII STL is human-readable plain text useful for debugging, scripting, or inspection. Both produce identical printed results. Choose binary unless you specifically need to read or edit the file by hand.
No. STL is a geometry-only format it stores triangle meshes with face normals but no color, texture, or material data. The STL output will be a monochrome mesh ready for slicing. If you need multi-color 3D printing, use OBJ directly in slicers that support it (PrusaSlicer, Bambu Studio with AMS), or export to 3MF format.
Our converter produces manifold, watertight meshes with consistent face normals. However, if the source OBJ has non-manifold geometry, holes, or degenerate faces, those issues may carry through. Always inspect your STL in the slicer's preview before printing. Use our Mesh Repair tool for any issues.
Absolutely. All uploads use TLS 1.3 encryption. Files are processed in isolated cloud environments and auto-deleted within 1 hour. Read our Privacy Policy for full details.
Free users: 50MB. Basic: 100MB. Pro: 500MB. Team: 1GB. Binary STL output will be compact ASCII STL can be 5-10x larger than binary.