Convert IPT to STL
An .ipt is an Autodesk Inventor part. Inventor’s STL export is under Export rather than Save As — the opposite of SolidWorks — and the quality settings are behind an Options button that is easy to walk straight past.
We cannot read .ipt files. The format is closed and Autodesk publishes no specification, so no browser tool opens one. Export from Inventor using the steps below, or ask the sender for a STEP file.
Exporting an STL from Inventor
Written for Inventor 2023 and later.
Open the part and find the export
File → Export → CAD Format…
Inventor puts mesh export under Export, CAD Format — not under Save As, and not under Print. This is the step people spend the longest looking for.
Choose STL
Save as type: STL Files (*.stl)
The Options button in the bottom corner of the dialog becomes active once STL is selected.
Open the options and set the resolution
Options… → Resolution: Custom → Surface Deviation · Normal Deviation
High, Medium, Low and Brep are presets. Custom gives you the two numbers that matter: surface deviation, which is how far a triangle may sit from the true surface, and normal deviation, which is the angle between neighbouring triangles.
For a part up to 100 mm, a surface deviation around 0.01 mm and a normal deviation of 5 to 10 degrees gives a smooth result at a reasonable size. There is also a Max Edge Length setting, which is worth leaving alone unless a downstream tool demands a triangle size limit.
Set the units and format
Units: Millimeter · File Format: Binary
Binary for size, millimetres because slicers assume them and STL cannot record a unit. If the part was modelled in inches, this dropdown is where the conversion happens.
Save and verify
OK → Save
Check the result in a converter here — the measured dimensions tell you immediately whether the unit dropdown did what you expected.
The Brep preset, and when to use it
Inventor offers a Brep option among the resolution presets, which is not a quality setting in the same sense as the others. It exports the boundary representation as faithfully as a mesh allows, using the modelling tolerance of the part rather than a tolerance you choose.
It is useful when you want the mesh to match the model as closely as the model itself is defined, and it is a reasonable choice for a small precise part. On a large model it can produce an enormous file, because it makes no allowance for the fact that nobody needs a large flat panel described to modelling tolerance.
For printing, Custom with explicit numbers is usually the better answer, because it lets you match the tolerance to what the printer can actually reproduce rather than to what the model happens to be defined at.
Assemblies, and the one-file-or-many question
An Inventor assembly is a .iam rather than a .ipt, and the same export path handles it. The dialog then offers the choice between one STL for the whole assembly and one per component.
As with SolidWorks, separate files are what you want for printing. A merged assembly STL has every mated surface passing through another, and a slicer cannot interpret that reliably. It is also, of course, a single unprintable piece.
If the assembly is going to someone else rather than to a printer, STEP carries the whole thing — geometry, structure, component names — in one file that opens anywhere.
If you do not have Inventor
Ask for STEP. Inventor writes it from the same Export, CAD Format dialog, and STEP opens in FreeCAD, Fusion 360, Onshape and every free viewer, with the exact surfaces intact.
Autodesk publishes a free viewer for its own formats, and Fusion 360 — which is free for personal use — can open Inventor files directly, since both are Autodesk products. That is the one route to opening an .ipt without Inventor itself, and it is worth trying before asking the sender for anything.
What will not work is any browser-based converter. The format is closed and the geometry sits on top of Autodesk’s own ASM kernel, which has no open implementation.
Where we can actually help
Once Inventor has given you an STL, the conversions after that run here in your browser — 3MF to record the units, or GLB to show somebody the part without them needing CAD software.
Questions
- Where is the STL export in Inventor?
- File, Export, CAD Format, then choose STL Files from the Save as type list. It is not under Save As, which is where SolidWorks puts it.
- What resolution should I pick?
- Custom, with a surface deviation around 0.01 mm and a normal deviation of 5 to 10 degrees for a part up to 100 mm. The High preset is usually finer than a 3D printer can reproduce.
- Can Fusion 360 open my .ipt?
- Yes. Both are Autodesk products and Fusion 360 imports Inventor files directly. Fusion is free for personal use, which makes it the practical route when you have no Inventor licence.
- What is the Brep resolution option?
- It exports at the part’s own modelling tolerance rather than a tolerance you choose. Good for small precise parts, potentially enormous for large ones. For printing, Custom with explicit numbers is usually better.
Where to go next
Related guides
Tools that do part of this here
About these formats
Checked against current software versions on 2026-09-11