3D Converter

Convert STL Meshes to OFF for Computational Geometry and Mesh Processing

Convert STL triangle meshes into the Object File Format for use in CGAL, MeshLab, Gmsh, OpenMesh, and other computational geometry and mesh processing tools that read OFF natively. Bridge 3D print geometry into research pipelines and geometry algorithm workflows.

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Convert STL Meshes to OFF for Computational Geometry and Mesh Processing
Free Tool

Convert STL to OFF

Upload a STL file and download the converted OFF — all processing happens on the server.

Drop your STL file here

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Accepts .stl files

An STL triangle mesh converted to OFF and processed in a computational geometry tool
01

From 3D Print Geometry to Computational Processing

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An OFF file structure viewed in a text editor alongside a rendered mesh
02

Minimal Plain-Text Format for Custom Parsing

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An STL mesh converted to OFF used as input for mesh simplification in MeshLab
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Mesh Repair, Remeshing, and Algorithm Input

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How It Works

How to Convert STL to OFF

1

Upload Your STL File

Drag and drop an STL file into the upload zone or click to browse. Both ASCII and binary STL files up to 100 MB are supported.

2

Sign In and Convert

Sign in to start the conversion. The server reads the STL triangle geometry and writes vertex positions and face indices into a clean OFF file.

3

Download the OFF File

Once ready, click Download. The OFF file is immediately usable in CGAL, MeshLab, Gmsh, OpenMesh, libigl, and any other computational geometry or mesh processing tool.

Deep Dive

STL and OFF: Print Triangle Format vs. Geometry Processing Format

STL and OFF: Print Triangle Format vs. Geometry Processing Format
01

STL: The 3D Printing Triangle Format

Stereolithography format was created in 1987 for 3D printing. It stores geometry as triangulated facets with outward-facing normals and no material, color, UV, or metadata support. It is the universal 3D printing standard but requires conversion for use in many computational geometry tools.

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OFF: The Minimal Geometry Exchange Format

The Object File Format stores vertex positions and polygon face indices in a minimal plain-text structure with no binary encoding and no material references. It is widely used in the computational geometry research community and supported natively by CGAL, MeshLab, Gmsh, OpenMesh, and libigl as a lightweight input and exchange format.

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When to Convert STL to OFF

Convert when you need to feed 3D print geometry into CGAL, MeshLab, or Gmsh as OFF input, when you want a minimal plain-text mesh representation for custom parsing or algorithm development, or when your research or engineering pipeline requires OFF input and the source file is in STL format.

Benefits

Why Use It

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No Software to Install

The conversion runs on the server. No MeshLab batch scripts, CGAL pipelines, or local Assimp CLI tools needed. Upload and download directly from your browser.

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Minimal and Parseable

OFF is a plain-text format with vertex positions and face indices and nothing else. The output is easy to parse with custom scripts or geometry libraries without format-specific library dependencies.

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Compatible with Geometry Tools

CGAL, MeshLab, Gmsh, OpenMesh, and libigl read OFF natively. The converted file integrates directly into computational geometry research and mesh processing pipelines.

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Print to Research Pipeline

STL is the 3D printing standard. OFF is the geometry processing community's compact exchange format. Converting STL to OFF bridges print geometry into computational geometry workflows for mesh repair, remeshing, and algorithm development.

Who Uses It

Who Converts STL to OFF

Who Converts STL to OFF
01

Computational Geometry Researchers

Convert STL triangle meshes to OFF for direct input into CGAL algorithms and mesh processing research workflows without additional format conversion overhead in the pipeline.

02

MeshLab Users

Convert STL files to OFF for mesh repair, simplification, and surface reconstruction operations in MeshLab, which reads OFF natively alongside STL for geometry processing tasks.

03

Gmsh Users

Convert STL print geometry to OFF for surface meshing and volume mesh generation in Gmsh, which accepts OFF as a direct geometry input format for meshing workflows.

04

Pipeline Engineers

Standardize incoming STL models to OFF for consistent geometry handling in computational geometry tool chains regardless of the source 3D printing slicer or CAD export version.

05

Geometry Algorithm Developers

Convert STL meshes to OFF for easy parsing in custom C++, Python, or research scripts that process triangle mesh geometry without requiring STL format library dependencies.

Related Tools

Frequently Asked Questions

Are both ASCII and binary STL files supported?

Yes. The converter handles both ASCII and binary STL input. Binary STL is more compact and the standard output of most CAD tools and slicers, but ASCII STL is also fully supported.

Does the OFF output preserve the STL triangle faces?

Yes. The triangle facets from the STL file are written as triangular faces in the OFF output, preserving the mesh topology from the source STL.

Does the OFF output include normals from the STL?

Standard OFF does not include per-vertex or per-face normals as separate entries. The vertex positions and face indices from the STL are written to the OFF file. Normals are not stored in the basic OFF format.

What tools read OFF files?

CGAL, MeshLab, Gmsh, OpenMesh, libigl, and many other computational geometry and mesh processing libraries and tools read OFF natively. It is a standard exchange format in the geometry processing research community.

What is the maximum STL file size?

The converter supports STL files up to 100 MB. OFF is an ASCII format, so the output may be larger than a binary STL source for the same geometry.

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Convert Your STL File to OFF Now

Upload your STL mesh and get a compact OFF file in seconds. No install, no manual steps.