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CAD File Format Encyclopedia

Your complete guide to 15 3D CAD and mesh file formats — what they store, where they are used, and how to convert between them.

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Free trial: 10 conversions with every feature. No credit card required. Windows 10/11.

What can I get from my file?

Find the kind of file you have and see what it can become

Your file
3D printingSTL · 3MF · OBJ · PLY
Web, AR and gamesglTF · GLB · FBX · DAE
ViewersVRML · X3D · OFF
CAD exchangeSTEP · IGES · BREP
Solid CADSTEP · IGES · BREP
3D printingYes
Web, AR and gamesYes
ViewersYes
CAD exchangeYes
MeshSTL · OBJ · 3MF · PLY · glTF · GLB · FBX · DAE · X3D · OFF · AMF
3D printingYes
Web, AR and gamesYes
ViewersYes
CAD exchangeNo
3D faces in drawings and scenes (read only)DXF · DWG · USD · USDZ
3D printingYes
Web, AR and gamesYes
ViewersYes
CAD exchangeNo
Native SolidWorks, Inventor or CATIA.sldprt · .ipt · .CATPart
Not read directly. Save as STEP in that program first, then every column above is open to you.
From the app's own format list (cadconvert formats, version 1.0.26). A mesh cannot become STEP, IGES or BREP: those need exact surfaces that a mesh does not store. A 2D-only DWG or DXF drawing has no 3D faces to convert.

Which format for which job

The jobWrite it asWatch for
  • Hand a part to a supplier or another CAD system
    • STEP
    • IGES
    • BREP
    Keeps the exact surfaces. A mesh cannot go back to STEP.
  • Print it
    • 3MF
    • STL
    • OBJ
    • PLY
    STL has no units or colour; 3MF carries both.
  • Show it in a web viewer
    • GLB
    • glTF
    GLB is one file; glTF puts the geometry in a separate .bin.
  • Load it in a game engine or renderer
    • FBX
    • OBJ
    • DAE
    Match the up axis: glTF and Unity use Y up, Unreal and Blender use Z up.
  • Open it in a simple or older viewer
    • X3D
    • OFF
    • VRML
    VRML opens from .wrl, .vrml or gzipped .wrz and exports as .wrl.
Read only, never written:
  • DXF
  • DWG
  • USD
  • USDZ
  • AMF
Checked against the 1.0.26 export list and by converting real files. Filled chips are the usual pick for the job.
What it will not do
  • Convert a 2D-only DWG or DXF drawing. It needs 3D faces.
  • Turn a mesh (STL, OBJ, 3MF) back into STEP, IGES or BREP.
  • Read native SolidWorks, Inventor or CATIA files. Export STEP or IGES from that program first.

Where each format came from

  1. CAD exchange1980IGESNBS
  2. 3D printing1987STL3D Systems
  3. CAD exchange1994STEPISO 10303
  4. Web and scenes1994VRMLVRML 1.0
  5. Scans and AR1994PLYStanford
  6. Web and scenes2004DAESony, COLLADA
  7. 3D printing20153MF3MF Consortium
  8. Web and scenes2015glTFKhronos
  9. Scans and AR2016USDPixarReads only
Year of each format's first public specification or release; STEP's first parts came out in 1994-95. Formats without a tag are read and written by 3D CAD Converter 1.0.27.

See it in action

From loading a STEP assembly to a finished batch — the same wizard handles every format on this page.

Step 1: selecting 3D files with a live 3D preview of the loaded STEP assembly
1. Load & preview — drop in files, inspect geometry instantly
Step 2: choosing multiple output formats — STL, OBJ and glTF checked for batch conversion
2. Pick formats — convert to several formats in one pass
Step 3: tessellation and conversion options with Fine preset and deflection controls
3. Set mesh quality — control tessellation, units and coordinate system
Step 4: conversion complete screen showing 6 of 6 files successfully converted
4. Done — export a CSV or HTML report, or open the output folder

Browse All 15 Formats

STEP .stp .step Solid / NURBS

Industry standard for precise 3D solid model exchange between CAD systems.

 IGES .igs .iges NURBS surfaces

Legacy NURBS surface format widely supported by aerospace and older CAD systems.

 STL .stl Mesh — 3D printing

The universal 3D printing format — simple triangle meshes readable by every slicer on the market.

 OBJ .obj Mesh + UV

Versatile mesh format with UV texture coordinates — the go-to for rendering and visualization.

 3MF .3mf Mesh + color + metadata

Modern 3D printing format with color, material, and multi-part support — better than STL in every way.

 glTF / GLB .gltf .glb Mesh + PBR — web/AR

The web standard for 3D — PBR materials, compact size, and native AR/VR support.

 FBX .fbx Mesh + animation

The game and VFX industry standard for animated assets — mesh, skeleton, and animation in one file.

 VRML .wrl Mesh + color — web 3D

Early web 3D standard — color meshes and scene hierarchy for virtual worlds and industrial viewers.

 DXF .dxf 2D/3D — CAD/CNC

Autodesk's universal CAD exchange format for 2D drawings, laser cutting, and lightweight 3D geometry.

 PLY .ply Mesh + attributes

Stanford polygon format with per-vertex attributes — ideal for point clouds and 3D scan data.

 BREP .brep .brp Solid / NURBS — OCC

OpenCASCADE's native exact-geometry format — the foundation for FreeCAD and OCC-based CAD tools.

 Collada DAE .dae XML scene format

XML-based scene format with animations and materials — used in game pipelines and robotic simulation.

 AMF .amf Mesh + color + material

ISO-standard XML format for 3D printing with color, curved triangles, and multi-material support.

 X3D .x3d XML — interactive web 3D

XML successor to VRML — interactive web 3D with animations and scripted behaviors.

 OFF .off Mesh — research

Minimal ASCII mesh format for computational geometry research and mesh processing tools.
DWG .dwg 2D/3D — AutoCAD native

AutoCAD native format. 2D drawings and 3D models used in architecture, engineering, and construction.

 USD / USDZ .usd .usdz Scene — Apple AR / Pixar

Pixar's scene format. USDZ powers Apple AR Quick Look, Vision Pro, and professional VFX pipelines.

Convert From Vendor-Locked CAD Formats

CATIA .CATPart .CATProduct Via STEP / IGES export

Open and convert CATIA V5/V6 exports (STEP, IGES) to STL, OBJ and glTF without a CATIA license.

 SolidWorks .sldprt .sldasm Via STEP / IGES export

Convert SolidWorks STEP/IGES exports to STL, OBJ and glTF in batch, no SolidWorks license needed.

 Inventor .ipt .iam Via STEP / IGES export

Convert Autodesk Inventor STEP/IGES exports to STL, OBJ and glTF in batch, no Inventor license needed.

Import vs. export: the formats below are the ones 3D CAD Converter reads. The formats you can convert to (export targets) are STEP, IGES, BREP, STL, OBJ, PLY, VRML, 3MF, glTF, GLB, DAE, FBX, X3D and OFF. STEP, IGES and BREP need a STEP, IGES or BREP source, because a mesh cannot become a solid. AMF, DXF, DWG and USD/USDZ are import-only: they cannot be selected as an output format.

Format Comparison

Format Type Open Exact geometry Color Animation Best for
STEP Solid / NURBS ✓ ✓ AP214+ ✗ Engineering exchange, archival
IGES NURBS surfaces ✓ ✓ Limited ✗ Legacy CAD, aerospace
STL Triangle mesh ✓ ✗ ✗ ✗ 3D printing, CNC
OBJ Polygon mesh ✓ ✗ Via MTL ✗ Rendering, visualization
3MF Triangle mesh ✓ ✗ ✓ ✗ Color 3D printing, additive mfg
glTF / GLB Triangle mesh ✓ ✗ PBR ✓ Web 3D, AR/VR, e-commerce
FBX Polygon mesh ✓ ✗ ✓ ✓ Game engines, VFX, animation
VRML Polygon mesh ✗ ✗ ✓ ✓ Industrial review, color sharing
DXF 2D/3D mixed ✓ Partial ✓ ✗ CAD drawings, laser cutting
PLY Polygon mesh ✓ ✗ ✓ ✗ 3D scanning, point clouds
BREP Solid / NURBS ✓ ✓ ✗ ✗ FreeCAD, OCCT tools
DAE XML scene ✓ ✗ ✓ ✓ ROS/Gazebo, SketchUp
AMF XML mesh ✓ ✗ ✓ ✗ Multi-material 3D printing
X3D XML scene ✓ ✗ ✓ ✓ Web documentation, e-learning
OFF Polygon mesh ✓ ✗ COFF variant ✗ Research, geometry processing
DWG 2D/3D mixed ✓ ✓ ✓ ✗ AutoCAD drawings, AEC
USD / USDZ Scene graph ✓ ✗ PBR ✓ Apple AR, VFX, e-commerce

Need to Convert Between These Formats?

3D CAD Converter imports all of these formats. Drop a folder, pick an output format, click Convert. AMF, DXF, DWG and USD/USDZ are import-only: you can convert from them. The export targets are STEP, IGES, BREP, STL, OBJ, PLY, VRML, 3MF, glTF, GLB, DAE, FBX, X3D and OFF.

Download Free Trial

Free trial: 10 conversions with every feature. No credit card required. Windows 10/11.