Convert Any 3D CAD File — STEP, IGES, STL, OBJ & 15+ Formats

How it works

Three steps, and no CAD license

You do not need SolidWorks, AutoCAD or Fusion to open the file.

Drop in the file
One part, an assembly, or a whole folder.
Look at it in 3D
Turn it, measure it, check the size before you convert.
Save what you need
Pick STL, 3MF, glTF or another format, then click Convert.

The 3D preview of 3D CAD Converter with a load cell STEP file open, showing the Wireframe, X-Ray and Measure controls, the parts list and the triangle count — Real screenshot: load_cell_LCE12.STEP (2.2 MB) open in 3D CAD Converter. 1 part, 228 faces, 15,714 triangles, 75.0 × 23.0 × 68.0 mm.

Formats

All the 3D Formats You Need

Your file first, then what your printer, viewer or supplier wants.

Your file

Solid CAD

STEP
IGES
BREP

Meshes

STL
OBJ
3MF
PLY
glTF
GLB
FBX
DAE
X3D
OFF
AMF

3D faces in drawings and scenes

DXF
DWG
USD

3D CAD Converteropens, previews, converts

What you get

3D printing

STL
3MF
OBJ
PLY

Web, AR and games

glTF
GLB
FBX
DAE

Viewers and archives

VRML
X3D
OFF

CAD exchange

STEP
IGES
BREP

Solid CAD (STEP, IGES, BREP) can become a mesh or another solid format. A mesh converts to other meshes. Dashed formats (DXF, DWG, AMF, USD) can be read but not written. VRML reads .wrl, .vrml and gzipped .wrz files and writes .wrl.

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.

Same part, two settings

Smooth curves or small files: you choose

A STEP file stores exact curves. An STL stores flat triangles, and one setting decides how many stand in for each curve.

The sensor housing drawn solid: rounded corners and a window cut in one wall

The same housing as a wireframe of 420 flat triangles: the rounded corners are a few large facets

Real output: housing_grove_scd41.stp (70 KB, 54 faces) converted at the Draft and Fine presets, rendered from the STL. Ultra Fine gives 73,508 triangles and 3.7 MB for no visible gain.

0.7 sa 70 KB STEP file to STL at the Fine preset
486,121triangles from a 19.7 MB STEP assembly
10free conversions before you pay
$179one payment, no subscription

Times and counts measured with 3D CAD Converter 1.0.22 and 1.0.23 on a Ryzen 9 3900X.

Watch a STEP file become a print-ready STL

Under 4 minutes: add the files, pick a mesh preset, switch on repair, convert.

Download Free Trial

Windows · free trial · pay once, no subscription

Professional 3D Conversion Tools

Convert and prepare 3D models for manufacturing, printing, visualization and archiving, in batch. Broken STEP and IGES surfaces are repaired before meshing.

Batch Format Conversion

Convert entire folders between any supported format. STEP to STL for 3D printing, IGES to STEP for CAD exchange, OBJ to 3MF for additive manufacturing. Drag-and-drop folders, set output format, click Convert. File naming templates with variables ({filename}, {format}, {date}).

Surface Repair & Polygon Reduction

Broken STEP, IGES and BREP surfaces are repaired before meshing: bad edges and faces are fixed and small gaps are sewn shut, so fewer holes reach the slicer. To cut polygon count, the command line option --decimate 0.25 keeps about a quarter of a mesh's triangles.

Unit & Coordinate System Conversion

Convert between mm, cm, inches, meters, and feet automatically during import. Fix axis orientation mismatches (Y-up to Z-up, left-hand to right-hand). Critical for multi-vendor CAD exchange where one team uses millimeters and another uses inches — a single wrong unit can ruin a $50,000 CNC run.

3D Preview & Inspection

Built-in 3D viewer with GPU-accelerated rendering. Inspect models before and after conversion. Wireframe, solid, and X-ray display modes. Measure distances, angles, and bounding boxes. Verify conversion quality without opening your CAD software.

Tessellation Control

Fine-tune STEP/IGES to mesh conversion with adjustable chord deviation, angular deflection, and maximum edge length. Preview tessellation quality in real-time. Low-poly output for web/game assets, high-poly for precision manufacturing. Quality presets: Draft, Standard, Fine, Ultra.

Metadata & Property Preservation

Preserve part names, colors, materials, and assembly structure during conversion. Extract metadata to CSV/JSON for BOM (Bill of Materials) generation. STEP AP214 product data, IGES entity labels, and STL solid names are all preserved where formats support them.

CLI & Automation

Full command-line interface for scripting batch conversions. Watched folder mode monitors an input directory and auto-converts incoming files. Profile files store conversion presets. JSON output for pipeline integration. Exit codes for CI/CD. Perfect for automated manufacturing workflows.

Assembly Support

Convert multi-part STEP and IGES assemblies preserving the part hierarchy. Export as a single merged mesh or individual parts in separate files. Assembly tree visualization shows all components with their transformations. Supports nested assemblies and external references.

Who it is for

Built-In Workflows for Every Industry

Pre-configured conversion pipelines tuned for specific industries and use cases. One click, production-ready output.

3D Printing / Additive Manufacturing

STEP/IGES to STL/3MF with surface repair before meshing and unit conversion (mm). Process entire job queues in batch. Tessellation presets from Draft to Ultra Fine set the mesh density.

CNC & Manufacturing

STEP/IGES to STL/OBJ/STEP with unit conversion and coordinate system alignment. Surface repair closes small gaps in STEP and IGES parts before meshing. Batch convert entire project folders.

Multi-Vendor CAD Exchange

Convert between vendor-neutral formats (STEP AP203/AP214) and native mesh formats. Fix unit mismatches, axis orientation, and assembly structure. Eliminate file-translation bottlenecks between engineering teams.

Web & Real-Time 3D

STEP/OBJ to glTF/GLB with tessellation control for web and game engines. Prepare CAD models for web configurators, AR experiences, and real-time 3D. Batch pipeline with CLI automation.

Archival & Documentation

Convert legacy formats to modern standards. IGES to STEP AP242 for long-term archival. Batch convert entire file libraries with consistent settings and naming conventions.

How 3D CAD Converter Compares

See how we stack up against CAD Exchanger, TransMagic, and Glovius.

Feature	CAD Exchanger ($590/yr)	TransMagic ($2,000+)	Glovius (subscription)	3D CAD Converter
Batch conversion	Limited	✔	✘	✔
Surface repair (STEP, IGES)	✔	✔	✘	✔
Unit conversion	✔	✔	✘	✔
3D preview	✔	✔	✔	✔
CLI automation	✔	✘	✘	✔
Tessellation control	✔	Limited	✘	✔
Assembly support	✔	✔	✔	✔
Fully offline	✔	✔	✔	✔
Cost	$590/yr	$2,000+	Subscription	One-time

CLI & MCP Server

Automate 3D format conversion from scripts, CI/CD pipelines, or AI agents. CLI and MCP server included with every license.

CLI Commands

Command	Description
`cadconvert convert`	Convert a single 3D file with format, quality, unit, and repair options
`cadconvert batch`	Batch convert a directory with parallel processing and format selection
`cadconvert info`	Inspect a 3D file — format, vertex/face counts, bounding box, units, assembly structure
`cadconvert formats`	List all supported input and output formats
`cadconvert watch`	Watch a folder and auto-convert new files as they arrive
`cadconvert register`	Activate your license key
`cadconvert serve`	Start the MCP server for AI agent integration (stdio transport)

# Convert STEP to STL with fine tessellation
cadconvert convert -i model.step -o model.stl --tessellation 0.01

# Batch convert with surface repair and unit conversion
cadconvert batch -i ./models -o ./out -f obj --repair --units mm

# Inspect a 3D file
cadconvert info assembly.step

# Watch folder for new files
cadconvert watch -i ./incoming -o ./converted -f 3mf

MCP Server — AI Agent Integration

Run cadconvert serve to start a Model Context Protocol server. AI agents like Claude can then convert, inspect, and query 3D files through natural language.

MCP Tool	Description
`convert_cad`	Convert a 3D file between any supported formats with quality, unit, and repair options
`get_file_info`	Get detailed file info — format, vertices, faces, bounding box, units, assembly tree
`detect_format`	Detect the format of a 3D file without full parsing
`list_formats`	List all supported input and output formats with capabilities

// claude_desktop_config.json
{
  "mcpServers": {
    "cadconvert": {
      "command": "cadconvert",
      "args": ["serve"]
    }
  }
}

Use it from your AI agent

3D CAD Converter ships an MCP server, so Claude Code, Cursor, Codex, VS Code and other agents that run on your PC can convert your CAD files through it. Your files stay on your computer.

# In Claude Code, two commands:
/plugin marketplace add contentasoftware/contentasoft-cad-converter-plugin
/plugin install contentasoft-cad-converter@contentasoft-cad-converter-plugin

It works during the free trial, with the same limits as the app. Plugin source on GitHub, launcher package on npm: GitHub · npm

Frequently Asked Questions

Is this a CAD Exchanger alternative?▼

Yes. 3D CAD Converter provides the same core functionality (batch conversion between STEP, IGES, STL, OBJ and 15+ formats, STEP and IGES surface repair, tessellation control and assembly support) as a one-time purchase instead of CAD Exchanger's $590/year subscription.

What 3D formats are supported?▼

STEP (AP203, AP214, AP242), IGES, STL (ASCII & binary), OBJ (with MTL materials), 3MF, VRML, DXF (3D), PLY, BREP, glTF/GLB, FBX, Collada (DAE), AMF, X3D, and OFF.

Can it repair meshes?▼

It repairs STEP, IGES and BREP parts before they become a mesh: broken edges and faces are fixed and small gaps between surfaces are sewn shut, so fewer holes reach the STL. It does not repair a mesh you already have (STL, OBJ, PLY). Fix that in a mesh editor or your slicer's repair function, then convert it.

Does it preserve assembly structure?▼

Yes — multi-part STEP and IGES assemblies are converted with full part hierarchy preserved. You can export as a single merged mesh or as individual parts in separate files.

Does it handle units?▼

Yes — auto-converts between mm, cm, inches, meters, and feet. Also fixes axis orientation mismatches (Y-up to Z-up, left-hand to right-hand coordinate systems).

Does it require CAD software?▼

No — 3D CAD Converter is fully standalone. No AutoCAD, SolidWorks, Fusion 360, or other CAD license is needed. It includes its own 3D viewer for inspecting models.

Is there a CLI?▼

Yes — full command-line interface for scripting batch conversions. Watched folder mode auto-converts incoming files. Profile files store conversion presets. JSON output and exit codes for CI/CD pipeline integration.

Does it work offline?▼

Yes — 100% offline. No cloud processing, no internet connection required, no file uploads. Your intellectual property stays on your machine.

How much will it cost?▼

$179 once, or $39 per quarter if you prefer to subscribe. Both include every feature. Try it first: 10 free conversions within 30 days, no credit card.

Start Converting Your 3D Files Today

Download the free trial or buy a license. No subscription, no cloud required.

Download Free Trial Buy Now — $179

Your STEP, IGES or STL file, opened and converted