What CADProps Is For: Inspecting CAD Files Online

A CAD file can be difficult to check when the person receiving it does not have the same desktop software as the person who made it. A supplier may need to confirm an overall dimension. An engineer may want to check whether a file contains a closed solid. A product team may need to compare two revisions before sending one onward.

That is the problem CADProps is built around. It is a web-based viewer and inspection tool for supported CAD and 3D files. The developer says it is free, and its core viewing and measuring tools do not require an account. Files are processed on the service's servers, so this is a browser front end for remote CAD processing rather than a lightweight desktop CAD application.

A browser inspection step, not a CAD replacement

The basic workflow is straightforward. Open a supported file, inspect the model in the viewer, check its dimensions and units, and examine the properties available for that format. CADProps supports several common engineering and mesh formats, including STEP, IGES, STL, OBJ, 3MF and static GLB or glTF files. It also lists native formats from SolidWorks, Siemens NX, Autodesk Inventor, CATIA, Parasolid and ACIS, along with JT and supported DWG or DXF drawings.

That breadth is useful when the immediate task is simply to see what is inside a file. DWG and DXF use a separate 2D viewer for layouts, filters and basic measurement. Assembly files may need their referenced parts packaged in a ZIP, and incomplete assemblies can produce warnings. Support still depends on the file version and its geometry, so the format list is not a guarantee that every file will open correctly.

The product is therefore best understood as an inspection checkpoint. It can help someone decide whether a file appears to be the right revision, whether its scale and units make sense, and whether it is ready to pass to another tool.

What the measurements can tell you

For a STEP or IGES file, CADProps says it calculates volume and surface area from B-Rep geometry. It can also estimate weight from a material density selected by the user. The calculation is volume multiplied by that density, which means the result depends on the model being a valid closed solid and on the user choosing the right material and units.

The viewer can show overall X, Y and Z dimensions, and users can switch between metric and imperial display units without changing the source geometry. Point-to-point measurements picked in the viewer are described as approximate. That distinction matters. An overall bounding dimension may be useful for a quick handoff check, while an approximate picked distance should not automatically become a manufacturing tolerance.

Mesh files have a larger qualification. STL, OBJ, 3MF and static GLB or glTF models can be inspected, but their measurements and surface properties come from triangle geometry. Volume and density-based mass are approximate and depend on a closed, consistent mesh. A damaged mesh can produce a result that looks precise while still being unsuitable for engineering decisions.

Conversion and comparison sit behind an account

CADProps also includes file comparison, batch property checks and format conversion in its advertised tool set. The access boundary is important: viewing and measuring are available without an account, while converting, saving files across devices and creating share links require sign-in. Only validated conversion outputs are offered, according to the developer.

That makes the service useful for a quick check before a handoff, but less like a fully anonymous conversion utility. If you need to upload a file, convert it and preserve access to the result across devices, expect to create an account. The landing page also says guest files expire after a displayed retention period, without specifying that period in the supplied material.

Privacy is another practical consideration. Original uploads are processed on CADProps servers, and the developer says private originals may be retained under its privacy policy. That does not automatically make the service unsuitable, but it does mean confidential designs should be assessed against the organisation's upload rules before use. A browser tool is not the same as keeping a file entirely on a local workstation.

Who should use CADProps

CADProps is aimed at makers, engineers and product teams that need a fast way to inspect supported files before sending them to a customer, supplier or another engineering system. It is a reasonable fit for checking dimensions, units, model properties, rough mesh measurements and the basic differences between files without installing desktop CAD software. The free access to core viewing and measuring also lowers the barrier for a recipient who only needs to examine a file.

It is not a native parametric modeller, so it will not replace a system used to edit feature trees or redesign parts. It is not a 3D printer slicer either. It also is not a strong fit when approximate mesh results are unacceptable, when a file must remain on local infrastructure, or when the required format or geometry falls outside its supported cases. CADProps makes most sense as an online CAD viewer and pre-handoff inspection tool, not as the main application for designing, manufacturing or safeguarding sensitive models.