Step 1
Open your STP model
Drop a .stp or .step CAD file into the converter. Nothing is sent to a server.
Free · Private · Browser-based
STP to STL Converter Online
Convert .stp CAD parts and assemblies into STL without installing a desktop CAD application. The browser processes your model locally and gives you control over mesh detail.
Drop STEP or STP file here
or browse your computer
Max 100 MB · processed locally
Your CAD file stays on this device. Only the converter engine is downloaded; model data is never uploaded.
How to convert STP to STL
Step 2
Control surface detail
Choose Draft, Balanced, or Fine depending on the curve smoothness and output size you need.
Step 3
Save the STL
Download the generated binary STL, or a ZIP containing separate STL files for an assembly.
STP and STL are different geometry types
STP is the three-letter extension commonly used for STEP files on systems that historically preferred shorter filenames. It contains the same ISO 10303 CAD data as .step, including exact surfaces and solids that must be tessellated before an STL can be created.
| Property | STP | STL |
|---|---|---|
| Geometry | Exact CAD surfaces | Triangle mesh |
| Units | Defined in the file | Not explicitly stored |
| Best for | CAD exchange and editing | Slicing and 3D printing |
STP to STL FAQ
What is an STP file?
An STP file is a STEP CAD exchange file using a three-letter extension. CAD systems use it to share exact solid and surface geometry.
Can Cura or a slicer open STP directly?
Most slicers expect a triangle mesh such as STL or 3MF. Convert STP to STL before importing it into your slicer.
Why does Fine quality create a larger file?
Fine tessellation uses more triangles to follow curved CAD surfaces closely, which improves smoothness and increases STL size.
Will model dimensions stay the same?
The CAD engine normalizes imported units to millimeters. Always verify final dimensions in the target slicer before production.
Same CAD format, different extension
Use the matching page if your filename uses the other common extension.