CAD File Formats — Pick the Right Tool for Each

DWG is the de facto interchange format for 2D and 3D CAD drawings. Originally developed for AutoCAD in 1982 and now maintained by Autodesk, the format stores vector geometry, layers, annotations, and limited 3D solid modeling data. Because DWG dominates the AEC and manufacturing CAD ecosystems, the ability to read and write it cleanly is the single most important interop feature for any 2D CAD tool. Below are every tool in our catalog that imports and/or exports DWG.

DXF (Drawing Exchange Format) is the open-spec sibling to DWG, designed in 1982 specifically for moving CAD data between applications. As an ASCII text format (binary DXF also exists), it's the lingua franca for laser cutters, plasma cutters, CNC routers, and any toolchain that needs to read CAD geometry without an AutoCAD licence. Every serious 2D CAD tool reads and writes DXF cleanly.

STEP (ISO 10303) is the international standard for exchanging 3D solid CAD data. Unlike DWG/DXF, STEP captures real B-rep solid geometry — meaning the receiving CAD tool gets the model's solid topology, not just surface meshes. This makes STEP the default format for cross-vendor mechanical design (SolidWorks ↔ Inventor ↔ Creo ↔ NX), and increasingly for 3D printing and CAM workflows where the kernel needs to do real surface analysis.

STL is the universal language of 3D printing. The format represents 3D geometry as a mesh of triangulated facets — simple, ubiquitous, and supported by every slicer and every printer. STL is lossy (no colour, no parametric history, no NURBS) but its simplicity is its strength: anything that can output STL can be 3D printed. Below are every tool in our catalog that imports or exports STL.

IGES is the older neutral CAD exchange format, predating STEP and historically used heavily in aerospace, automotive, and shipbuilding workflows where surface geometry (not solids) was the primary representation. IGES carries NURBS surfaces, curves, and analytic primitives, but lacks STEP's solid topology and PMI. Most mechanical CAD tools still read and write IGES for backwards-compatibility with legacy data.

IFC is the open BIM data standard maintained by buildingSMART International. Where DWG carries lines and STEP carries solids, IFC carries semantically-rich building models — walls know they are walls, doors know they are doors, slabs reference their floor level. This makes IFC the cornerstone of BIM-to-BIM interoperability and the required format for openBIM submissions to governments and large-firm collaboration. IFC4 is the current production version; IFC4.3 adds infrastructure (roads, rails, bridges) support.

OBJ is the universal interchange format for 3D mesh data with materials. Originally from Wavefront Technologies in the 1980s, it became the standard for moving 3D models between modelling, animation, and rendering applications. Unlike STL, OBJ carries textures, materials (via .mtl), vertex normals, and UV coordinates — making it the format of choice for visualisation, game asset pipelines, and 3D scanning output.

PDF in the CAD world is more than just a print format — it's the lingua franca for stakeholder review. PDF carries vector geometry, layers, annotations, and (in 3D PDF / U3D / PRC variants) full 3D model data with measurement and section tools. Most CAD tools export PDF for plotting, markup, and digital sign-off, while specialist tools like Bluebeam Revu and Adobe Acrobat handle the review/markup side of the workflow.

FBX is Autodesk's proprietary scene-and-animation interchange format. It carries 3D meshes, materials, rigs, animations, lights, and cameras — everything a game engine or animation pipeline needs. FBX dominates the games/film/animation toolchain (Unity, Unreal, Maya, 3ds Max), and increasingly architectural visualisation workflows where you need full scene fidelity (lights + materials + animation) not just geometry.

JT is the lightweight 3D visualisation format used heavily in automotive and aerospace mechanical design. Maintained by Siemens (and an ISO standard, ISO 14306), JT is designed for huge assembly visualisation — millions of parts, level-of-detail mesh data, attached PMI. It's the format of choice for digital-mockup workflows at the OEM level, particularly in supply chains anchored to Siemens NX and Teamcenter PLM.

The 3DM format is the native file type of Rhinoceros 3D, the industry standard for NURBS-based mathematical 3D modeling, industrial design, and computational architecture. Because 3DM files store precise double-precision NURBS curves, surfaces, and solids, they maintain perfect geometric fidelity without the mesh tessellation loss of formats like STL. The format is open-source (via the openNURBS initiative), allowing a wide variety of CAD, rendering, and rapid prototyping tools to import and export Rhino models directly. Below are all the tools in our catalog that support the 3DM format.

The 3D Manufacturing Format (3MF) is the modern, open-standard file format designed specifically for additive manufacturing and 3D printing. Developed by the 3MF Consortium (which includes Autodesk, Microsoft, HP, and UltiMaker), 3MF addresses the severe limitations of the legacy STL format. It is a clean, XML-based format that packs full scene geometry, scale units, color gradients, materials, textures, and internal lattice structures into a single compressed archive. Below are the tools in our catalog that support importing, exporting, or slicing 3MF files.

SLDPRT and SLDASM are the native, proprietary file formats used by Dassault Systèmes SolidWorks to store individual part files and multi-component assembly data. Since SolidWorks is the most widely adopted mechanical CAD program in the world, these formats contain critical feature-history trees, equations, assembly mates, and design parameters. Because they are native and proprietary, direct interoperability with other CAD kernels often requires translation, making them the most frequently searched formats for viewing and format conversion. Below are the tools in our database that support or convert SolidWorks files.

IPT and IAM are the native file formats for Autodesk Inventor, storing 2D/3D sketches, parametric features, physical material properties, and complex hierarchical assemblies (IAM). Highly optimized for Autodesk's proprietary modeling engine, these files maintain design history and constraints. While sharing them with non-Autodesk users often requires translation to neutral formats, their direct support in modern downstream simulation (CAE) and manufacturing (CAM) pipelines is vital for collaborative industrial engineering.

RVT is the native project file format of Autodesk Revit, the industry-dominant BIM authoring platform. A single RVT file acts as a relational database, storing all structural designs, architectural components (walls, windows, doors), MEP pipe routings, sheets, scheduling, and 3D visualization data. Because Revit models are extremely complex and carry rich semantic metadata, opening and sharing RVT files without software incompatibility is one of the most critical challenges in modern AEC project coordination.

DGN is the native file format of Bentley Systems MicroStation and its vertical civil infrastructure design suites. Originally developed in the 1980s, the DGN format (specifically V8 DGN) is widely recognized as the format of record for large-scale, long-lifecycle civil engineering projects, including highways, railways, bridges, and plant designs. Known for its incredible stability with massive datasets, DGN is the standard format for major transport departments and civil engineering consortia globally.

G-Code (often saved as .gcode, .nc, or .cnc) is the universal, standardized programming language used to control automated machine tools. Generated by CAM (Computer-Aided Manufacturing) software or 3D printer slicers, a G-Code file contains line-by-line coordinates, speeds, feeds, tool changes, and temperature parameters that command a CNC mill, lathe, laser cutter, or FDM 3D printer exactly how to move and fabricate a physical object from digital geometry.

X_T (ASCII) and X_B (Binary) are the native geometric kernel formats for Siemens Parasolid, the modeling engine that powers SolidWorks, Siemens NX, Solid Edge, Onshape, and over 300 other commercial CAD applications. Because it represents precise boundary representation (B-Rep) solid geometry, Parasolid files are the highest-fidelity neutral exchange format for transferring models between systems sharing the Parasolid kernel. Using X_T avoids the typical translation errors and topology issues that occur when converting to generic formats.

SAT (ASCII) and SAB (Binary) are the native geometric kernel exchange formats of the ACIS modeler, developed by Spatial Corporation (a Dassault Systèmes subsidiary). ACIS is the core geometric engine behind Autodesk AutoCAD, BricsCAD, Inventor (partially), and various specialized CAE/CAM applications. SAT files store precise mathematical descriptions of 3D solids and surfaces, providing robust interop for applications utilizing the ACIS kernel.

Universal Scene Description (USD), developed by Pixar and standardized for web/mobile as USDZ by Apple, is an open, extensible, and high-performance 3D scene description format. While traditional CAD formats focus strictly on solid geometry, USD is designed for collaborative, multi-layered 3D scenes—packing meshes, materials, lighting, cameras, animations, and AR capabilities. In 2026, USD is rapidly becoming the standard for exporting architectural designs and industrial CAD assets into real-time rendering engines, VR/AR platforms, and spatial computing environments.

DWF and DWFx are highly compressed, secure, and metadata-rich file formats developed by Autodesk specifically for multi-disciplinary design review, construction estimation, and secure plan distribution. Unlike raw DWG files, which carry complete editable CAD coordinate history and proprietary block geometry, DWF acts as a 'digital blueprint'. It preserves exact vector scale, layer names, and hierarchical block attributes while locking down coordinates from direct drawing modifications, making it the standard for sending construction sets to subcontractors and quantity surveyors.

EXB is the native file format of CAXA Electronic Draft, a leading Chinese CAD platform widely deployed across China's heavy industrial manufacturing, machining, and engineering education sectors. Built to align strictly with Chinese national drafting standards (GB standards), EXB files house detailed 2D production plans, localized dimension styles, annotated welding symbols, and structured BOM (Bill of Materials) systems that map directly to enterprise ERP systems.

VDA-FS (often saved as .vda) is a neutral 3D CAD data exchange specification defined by the German Association of the Automotive Industry (Verband der Automobilindustrie). Developed specifically to bypass geometric modeling engine discrepancies between CATIA and Siemens NX at the OEM level, VDA-FS is specialized for transferring highly complex mathematical Class-A surface geometry, freeform styling contours, and injection mold parting surfaces without translation errors.

CGR (CATIA Graphical Representation) and its web-friendly packaging format, 3DXML, are lightweight, tessellated 3D visualization formats developed by Dassault Systèmes. Engineered to enable digital mockup (DMU) reviews of massive industrial assemblies, CGR files strip away the heavy, precise mathematical B-Rep (boundary representation) solid definitions. What remains is a highly optimized polygonal mesh shell that can be loaded in thousands of instances concurrently inside CATIA, ENOVIA, or web-based PLM platforms to perform clearance checks, clash analysis, and layout coordination.

CATPart and CATProduct are the native geometric modeling formats of Dassault Systèmes CATIA, the high-end PLM software suite dominant in the global aerospace, defense, and automotive OEM sectors. A CATPart stores mathematically perfect solid models, complex multi-patch Class-A surfaces, functional tolerances, and tooling definitions built on Dassault's proprietary CGM (Convergence Geometric Modeler) engine. A CATProduct manages the assembly hierarchies, positioning coordinates, and links to external parts. Because of their advanced mathematical structure, opening these files directly in mid-range CAD engines requires certified translation layers.

NX PRT is the native database file format of Siemens NX (formerly Unigraphics), a high-end enterprise CAD/CAM/CAE system. Unlike mid-range CAD platforms that split components into separate part (.sldprt) and assembly (.sldasm) formats, NX uses a unified .prt extension for parts, assemblies, CNC toolpaths, and finite element meshes. Built natively on the Parasolid geometric kernel, NX PRT files are designed to manage massive product structures and maintain absolute downstream parametric associativity throughout the entire lifecycle.

Creo PRT and ASM are the native formats of PTC Creo (historically Pro/ENGINEER), the platform that pioneered history-based parametric 3D CAD modeling. These files store precise double-precision boundary representation (B-Rep) solids, parametric relationships, equations, and assembly constraints. Known for its mathematically rigorous handling of complex mechanisms and sheet metal flat patterns, the Creo file format maintains active, bi-directional links between the 3D model, downstream structural simulations, and CNC manufacturing toolpaths.

SLDDRW is the native 2D technical drawing sheet format utilized by Dassault Systèmes SolidWorks to generate manufacturing-ready documentation. While sldprt and sldasm represent the 3D model, SLDDRW files store the associated 2D projection views, detailed section cuts, dimensions, welding symbols, and BOM tables. SLDDRW files maintain a live, bidirectional link to the 3D database: if you modify a sketch dimension on the 3D part, the 2D sheet dimensions update automatically.

IDW is the native 2D drafting sheet format used by Autodesk Inventor to compile production-ready blueprints, section specifications, and assembly detail bills. It maps 3D parametric components directly onto 2D drawing sheets. IDW files maintain absolute associativity with the parent IPT (parts) and IAM (assemblies) files, automatically redrawing viewport projections, centerlines, and dimension callouts whenever the parent 3D components are modified.

F3D and F3Z are the native export formats of Autodesk Fusion 360, a cloud-first CAD/CAM/CAE platform. Since Fusion 360 stores projects by default in Autodesk's cloud servers, F3D acts as a local backup archive for an individual part. F3Z is a zipped container used for assemblies, archiving the top-level model along with all externally referenced part files. These archives contain full parametric feature trees, multi-body geometry, simulation meshes, rendering parameters, and CNC CAM toolpaths.

SKP is the native file format utilized by Trimble SketchUp, a widely popular 3D modeling application used in architecture, interior design, civil engineering, and video game development. SKP files store 3D models composed of faces and edges (polygon mesh representation) rather than parametric solid kernels. SKP documents are designed for rapid conceptual sketching, supporting custom materials, component libraries, scenes, and geographic styles.