CAD Assistant — The Complete Guide: Free Viewing and Conversion of STEP, IGES and glTF
CAD Assistant is a program from Open Cascade, the company behind the OpenCascade kernel, for opening, inspecting and converting CAD and mesh files. It is especially useful when you receive a model in a neutral format and want to check it or move it to another format without a full CAD program.
CAD Assistant
Open Cascade SAS
Free viewer and converter for STEP, IGES, BREP, glTF, STL and OBJ files, built on the OpenCascade kernel, commercial use included.
Get it from the vendorWhat you get
- Format reading — STEP including AP242, IGES, BREP, glTF, OBJ, VRML, PLY, FBX, 3DS and 3DM.
- Saving — to STEP, IGES, glTF, OBJ, PLY, STL and BREP.
- View-only formats — IFC, JT, ACIS, DXF and Parasolid files open for display.
- Conversion for printing and presentation — from STEP to STL or glTF in a few clicks.
- All platforms — Windows, macOS and Linux, plus mobile versions.
What to know: licence and updates
The program is free for personal and commercial use, with no registration, and is provided as is without warranty; the full licence terms come with the installer. The latest version was released in October 2021, and the software has not been updated since. It still works well for most files, but do not expect support for new formats or bug fixes.
Related tools
For viewing in the browser with no install — Online 3D Viewer. For the volume, weight and dimensions of a CAD file — CADProps. For a fast, actively maintained local viewer — F3D.
Online 3D Viewer
Online 3D Viewer project
Open STEP, IGES, IFC, STL, OBJ and more in the browser — files are processed locally, not uploaded to a server.
Get it from the vendor
CADProps — View and Measure CAD Files in the Browser
CADProps
Open STEP, IGES, SolidWorks and more in the browser and measure dimensions, volume, surface area and weight — free, no install, no account.
Get it from the vendor
F3D
F3D-APP Foundation
Fast, minimalist 3D viewer — STEP, STL, OBJ, glTF and PLY, including thumbnails in the file manager.
Get it from the vendor
FreeCAD
FreeCAD Project
Open-source parametric 3D modeller with workbenches for solid modelling, FEM, drafting and BIM.
Get it from the vendorThe bottom line
A reliable viewer and converter for neutral formats, free for commercial work too. It is no longer developed, but it remains very useful for checking and converting STEP and IGES.