What is a .ipt file?

What an Inventor part contains

An IPT is the Inventor equivalent of a SolidWorks part, and the two are organised the same way. Inside is the finished solid, held in Autodesk's ShapeManager kernel (a descendant of ACIS that Autodesk has developed separately since 2001), and the model browser that records how it was built: sketches, extrusions, holes, fillets, patterns and their driving dimensions. Change a dimension and the part rebuilds.

Alongside those are the document's units, set per file and defaulting to whichever template it was started from, the material and appearance, iProperties (title, part number, custom fields) that flow into bills of materials, and often iParts, which are tabulated variants of one part driven from an embedded spreadsheet.

What another CAD system imports is the solid alone. Fusion, SolidWorks and Onshape read Inventor parts, and each of them gets a dumb solid without the browser tree.

The family of files

A part is .ipt. An assembly is .iam, which holds constraints and references to part files by path, and no geometry of its own. A drawing is .idw (or .dwg from Inventor, which is not quite the same as an AutoCAD DWG). A presentation, for exploded views, is .ipn. All of them are OLE compound documents, which is why Windows shows a thumbnail for them.

Send an .iam without its parts and the recipient gets an empty assembly with unresolved references. Inventor's Pack and Go collects everything an assembly needs into one folder.

Versions

Inventor releases yearly and is not backward compatible. A part saved in Inventor 2026 will not open in Inventor 2025, and there is no "save as previous version" for parts. The reliable answer is a STEP export from the newer installation.

Where these files come from

Machine design and industrial equipment, in shops that standardised on the Autodesk product line, often alongside AutoCAD for the 2D drawings. Manufacturer part libraries offer IPT downloads less often than STEP or SolidWorks, so an IPT usually comes from the person who designed it.

Getting geometry out

Inside Inventor: Save Copy As, and choose STEP, IGES, SAT, STL, OBJ or 3MF. Inventor also writes Parasolid and a CATIA V5 part directly. For STEP, AP214 is the default and AP242 is available; both carry colour.

Without Inventor, Autodesk Viewer shows the part in a browser and measures it but does not convert. Fusion opens an IPT and exports STEP, and its personal-use licence is free, which is the usual no-cost route. Onshape's free plan imports it and exports STEP as well.

How to open a .ipt file

Autodesk Viewer displays an Inventor part in a browser at no cost, with measurement and sectioning, and eDrawings does the same free on Windows. Fusion opens IPT files, and its personal-use licence is free. Onshape's free plan imports them. This site cannot read the format.

To edit the model with its parameters and feature history you need Inventor, which runs on Windows only. SolidWorks imports Inventor parts as geometry.

Inventor is not backward compatible. A part saved in Inventor 2026 will not open in Inventor 2025, and there is no option to save as an older release. The sender has to export STEP instead. An assembly is an .iam that references its parts by path, so an assembly sent without its .ipt files opens as an empty tree.