CAD & 3D File Formats Guide

Format Comparison Table

DWG — AutoCAD Drawing

Extension: .dwg | Type: Proprietary binary | Developer: Autodesk

DWG is the native file format of AutoCAD and the most widely used format for 2D CAD drawings. It stores geometric entities, layers, blocks, dimensions, text, and metadata in a compact binary format. DWG is the industry standard for architectural floor plans, engineering schematics, and construction documents.

Use cases: Architectural design, mechanical engineering, electrical schematics, civil engineering, construction documentation.

DXF — Drawing Exchange Format

Extension: .dxf | Type: Open (ASCII or binary) | Developer: Autodesk

DXF was created by Autodesk as an interchange format for sharing CAD data between different software applications. The ASCII version is human-readable and can be parsed by any text editor. DXF supports nearly all the same entities as DWG but in a documented, open format. It is the most universally supported CAD format.

Use cases: Cross-platform CAD file sharing, CNC machining, laser cutting, programmatic CAD generation, open-source CAD workflows.

STL — Stereolithography

Extension: .stl | Type: Open (ASCII or binary) | Developer: 3D Systems

STL describes the surface geometry of a 3D object as a collection of triangular facets. It does not store color, texture, or material information — only raw geometry. STL is the standard format for 3D printing and rapid prototyping. It is simple to parse and supported by virtually all 3D printing software and slicers.

Use cases: 3D printing, rapid prototyping, CNC milling, quality inspection, finite element analysis.

OBJ — Wavefront Object

Extension: .obj | Type: Open (ASCII) | Developer: Wavefront Technologies

OBJ is a widely supported 3D model format that stores vertices, faces, normals, and texture coordinates. It can reference external MTL (material) files for colors and textures. OBJ supports polygonal meshes with more than 3 sides (unlike STL which only supports triangles). It is a standard exchange format in 3D modeling and animation.

Use cases: 3D modeling, game development, visual effects, 3D scanning output, academic research.

glTF / GLB — GL Transmission Format

Extension: .gltf, .glb | Type: Open (Khronos) | Developer: Khronos Group

glTF is often called the "JPEG of 3D" because it is designed for efficient transmission and loading of 3D scenes. It supports meshes, materials (PBR), textures, animations, cameras, and lights in a single package. GLB is the binary container version that bundles all assets into one file. glTF is the preferred format for web, AR/VR, and real-time applications.

Use cases: Web-based 3D, augmented reality, virtual reality, product configurators, digital twins, e-commerce.

FBX — Filmbox

Extension: .fbx | Type: Proprietary | Developer: Autodesk (originally Kaydara)

FBX is a versatile 3D file format that supports meshes, materials, textures, animations, bones/rigging, cameras, and lights. It is widely used in the game development and film production industries for exchanging assets between modeling, animation, and rendering software. FBX comes in both binary and ASCII variants.

Use cases: Game development (Unity, Unreal Engine), film and VFX, motion capture data, character animation, architectural visualization.

3DS — 3D Studio

Extension: .3ds | Type: Proprietary | Developer: Autodesk

3DS is a legacy format from the original 3D Studio DOS application (predecessor to 3ds Max). It supports meshes, materials, cameras, lights, and basic animations. While largely superseded by FBX and glTF, 3DS files are still encountered in legacy archives and older CAD/3D workflows.

Use cases: Legacy 3D data exchange, older CAD workflows, simple 3D model sharing.

STEP — Standard for the Exchange of Product Data

Extension: .step, .stp | Type: Open (ISO 10303) | Developer: ISO

STEP is an ISO standard for representing 3D product manufacturing information. Unlike mesh-based formats, STEP stores exact mathematical representations of curves and surfaces (NURBS, B-splines), making it the gold standard for engineering and manufacturing interoperability. It preserves precise geometry across different CAD systems.

Use cases: Manufacturing (CAD/CAM/CAE), mechanical engineering, aerospace, automotive, product lifecycle management.

IFC — Industry Foundation Classes

Extension: .ifc | Type: Open (ISO 16739) | Developer: buildingSMART

IFC is the open standard for Building Information Modeling (BIM). It stores not just 3D geometry but also rich semantic data about building elements — material properties, structural relationships, cost information, scheduling data, and more. IFC enables interoperability between different BIM software like Revit, ArchiCAD, and Tekla.

Use cases: BIM workflows, building design coordination, clash detection, facility management, regulatory compliance.

Choosing the Right Format

Selecting the right file format depends on your specific workflow and requirements:

• 2D architectural/engineering drawings: DWG or DXF
• Cross-platform CAD exchange: DXF or STEP
• 3D printing: STL or 3MF
• Web/AR/VR 3D content: glTF/GLB
• Game development: FBX or glTF
• Manufacturing/CNC: STEP or DXF
• BIM/Building design: IFC or DWG
• General 3D model sharing: OBJ or glTF

Frequently Asked Questions