CAD Assistant

CAD Assistant is a free, offline 3D CAD viewer and converter for personal and commercial use. It opens CAD and mesh formats including STEP, IFC, IGES, BREP, glTF, JT, PLY, STL, OBJ, 3DM, DXF, SAT, and Parasolid XT. Users can browse assembly trees, toggle components, and inspect product or geometric properties such as area, volume, and centroid. For PLY meshes, it offers wireframe, shaded, and shrink views, with color or scalar values mapped to mesh elements or nodes. Desktop editions also include a GPU-accelerated path-tracing renderer for screenshots. The maker says files are processed locally and that a server connection is not needed. Imports supplied by commercial Open Cascade components cannot be exported or converted, although the maker says models retain their full structure without model-size limits. Large files may take time to load, low-range GPUs may be slow, and scenes with several million triangles may be stopped by the system. The product page lists version 1.6.0, dated 2021-10-05, as the latest release.

CAD Assistant offers broad format support and model inspection without requiring a server connection. Check the commercial-import restriction and device limits if export or large-scene work matters.

It suits people who need to view or inspect CAD and mesh files on desktop or mobile devices, including users who prefer local, offline processing. It can also serve personal and commercial use, subject to the import-related export and conversion restriction.

CAD Assistant is a free, offline viewer and converter for people who need to inspect CAD assemblies and mesh files on desktop or mobile. Its breadth of formats and useful model-inspection tools make it a capable general-purpose viewer, but restrictions on some imports limit its role as a conversion tool.

Overview

CAD Assistant combines model viewing, structural inspection and conversion in one app for personal and commercial use. It supports formats including STEP, IFC, IGES, BREP, glTF, JT, PLY, STL, OBJ, 3DM, DXF, SAT and Parasolid XT. That mix is useful when work arrives in different CAD and mesh formats, though format support alone does not guarantee that every imported model can be exported.

Processing takes place locally, with no server connection required. The current listed release is version 1.6.0, dated 2021-10-05.

Key features

Assembly and geometry inspection

Users can browse assembly trees, show or hide components, and inspect product and geometric properties such as area, volume and centroid. That makes CAD Assistant more useful than a basic file preview when the task is to understand how a model is organized or check its measurements.

Mesh analysis and desktop rendering

For PLY meshes, wireframe, shaded and shrink modes offer different ways to examine the geometry; color or scalar quantities can be mapped to mesh elements or nodes. Desktop versions also include a GPU-accelerated path-tracing renderer for photo-realistic screenshots. The renderer is a welcome option for presentation images, but low-range GPUs may run slowly.

Conversion has an important boundary

CAD Assistant includes conversion, but imports provided by commercial Open Cascade components cannot be exported or converted. Users should treat it as a strong inspection tool and confirm import eligibility before relying on it for file handoffs.

Local workflow conveniences

Operating-system file associations let compatible apps open relevant files in CAD Assistant, and saved model images can be attached through a mail client. Those small workflow links complement the offline model processing without requiring a server connection.

Pricing

CAD Assistant — free. The free plan covers personal and commercial use, with no seat count, quota or trial term stated. The key trade-off is functional rather than a paid-plan upgrade: commercial-component imports restrict model export and conversion. Its free license makes it easy to use for inspection, but teams that need dependable conversion across all supported formats should consider another tool.

Platforms

CAD Assistant supports Windows, macOS, Linux, iOS and Android. Broad device coverage is useful for viewing models across desktop and mobile, but demanding scenes remain subject to device performance: large files may take time, scenes with several million triangles may be terminated by the system, and files under 50 MB are generally safe on most devices.

Who it's for

CAD Assistant suits engineers, designers and other users who need a no-cost local viewer for mixed CAD and mesh files, assembly structure, geometric properties or PLY data. It is less suitable as a universal conversion pipeline, or for large, triangle-heavy scenes on lower-powered hardware. Support is directed through forums and contact options for bug reports, questions and suggestions; the application is provided as is, without warranty.

Pros and cons

• Pro: Broad CAD and mesh format support makes it useful for inspecting files from varied workflows.
• Pro: Assembly browsing and geometry properties provide meaningful inspection beyond simple viewing.
• Pro: Local processing and free personal and commercial use suit users who want an offline utility without a recurring charge.
• Con: Commercial-component imports cannot be exported or converted, which can block a key handoff workflow.
• Con: Large scenes can be slow or terminated on constrained devices, despite the maker's claim of no model-size limit.
• Con: The listed release dates to 2021, so buyers seeking a more recently listed version may want to compare alternatives.

Alternatives

3D File Converter Software is a useful starting point for comparing conversion-focused options.

• HOOPS Exchange is worth considering when paid access and technical expert support matter: its evaluation offers full access for 60 days, with support included.
• ODA File Converter is another free option for readers interested in a tool from a non-profit CAD and BIM interoperability consortium.
• CAD Exchanger may suit readers who want perpetual or subscription licensing and node-locked or floating license options; pricing is custom pricing.
• Open Asset Import Library (Assimp) is a free alternative for software projects that can comply with its modified three-clause BSD license, including the requirement to include the license text with the product.
• 3D-Tool is a Windows-only choice if opening DDD, STL and 3MF files is enough; its free viewer cannot export CAD files.
• Convert3D is a fit for API users who can work within the Free API's 10 conversions/month, or need the Starter plan's 5,000 conversions/year at $899 a year.
• Spin 3D is an option for macOS, web or Windows users who need a free version for non-commercial use.
• 3D Model Converter is a browser-based alternative whose free plan supports unlimited browser-local mesh workflows, plus five cloud credits per month and a 50 MB cloud-file cap.

Verdict

Choose CAD Assistant if you want a free, local viewer for a wide range of CAD and mesh files, with assembly inspection and useful geometry properties across desktop and mobile. Its main advantage is the combination of broad format support and offline use; look elsewhere if you need reliable export or conversion for imports handled by commercial Open Cascade components, or routinely work with very large scenes.