Convert STP to PLY
Free, in your browser, with nothing uploaded. Drop your .stp file in and take the .ply away.
Drop your STP file here
.stp in, .ply out
Choose filesNothing is uploaded No account, no email No file size limit
How to convert STP to PLY
- 01
Add your .stp file
Drag your STEP (ISO 10303) file onto the drop zone, or click it to browse. Nothing is uploaded: it is read where it already sits.
- 02
Check the preview
The model is parsed on your machine and drawn in the viewport, so a wrong axis or a missing texture shows up before you commit rather than downstream.
- 03
Save the .ply file
Press convert. The Polygon File Format file is written in the tab and lands in your downloads folder. No link, no expiry, no account.
What carries over, and what does not
A format conversion is a translation, and translations lose things. Here is what actually happens when an STP file becomes a PLY file.
| Data | STP | PLY | Survives |
|---|---|---|---|
| Geometry | Yes | Yes | Yes |
| Materials & colour | Yes | No | Dropped |
| Texture maps | No | No | n/a |
| Animation & rigs | No | No | n/a |
| Scene hierarchy | Yes | No | Dropped |
Expect to lose
- PLY stores geometry only, so materials and colours are dropped.
- The scene hierarchy is flattened: separate objects in the STP file are merged into one mesh.
None of this is a defect in the conversion; it is what PLY is specified to hold. If you need the missing data, convert to GLB instead, which carries geometry, PBR materials, textures and animation in a single file.
About STEP (ISO 10303)
A .stp file is a STEP file; the extension was clipped to three characters for the sake of DOS-era tooling, and both spellings still come out of the same exporters. Everything true of .step is true here: ISO 10303 boundary-representation solids, tessellated into triangles on the way out.
Commonly seen in: SolidWorks, Fusion 360, CATIA, Siemens NX, FreeCAD. More on the STP format page.
About Polygon File Format
PLY, the Stanford Triangle Format, was designed to hold the output of 3D scanners, and it shows: it stores arbitrary per-vertex properties, so colour, confidence and intensity ride along with position. It is the standard exchange format for photogrammetry and lidar work, and the format the Stanford Bunny ships in. Both an ASCII and a compact binary variant exist; the binary one is what you want for anything above a few hundred thousand points.
Commonly seen in: MeshLab, CloudCompare, RealityCapture, Agisoft Metashape, COLMAP. More on the PLY format page.
How the conversion works
When you drop a file in, the bytes are handed to a parser compiled to run in your browser. The STP data is decoded into an in-memory scene graph of meshes, materials and transforms, which is what the preview is drawing. Pressing convert walks that scene graph back out through a PLY writer and hands you the resulting bytes as a download.
The whole round trip is local. The page itself is static: it is delivered once and then does its work offline. That is why the privacy claim is checkable rather than a promise.
STP to PLY: common questions
Is my STP file uploaded anywhere?
No. The file is read by code running inside this browser tab and never crosses the network. You can prove it by disconnecting from the internet before you convert, the page keeps working, or by watching the Network tab in your browser's developer tools while you drop a file in.
How large an STP file can I convert?
There is no server-side limit because there is no server. The practical ceiling is your own machine's memory: a browser tab can usually handle models up to a few hundred megabytes. Very dense scans or scenes with millions of triangles will take a few seconds and a lot of RAM.
Why does my converted PLY file look untextured?
PLY stores geometry only; it has no way to record materials or texture maps. If you need the surfacing to survive, convert to GLB or glTF instead.
Does it cost anything?
No. There is no fee, no account, no watermark and no per-file limit. Since the conversion runs on your hardware rather than ours, serving this page costs about as much as serving a blog post.
Does it work on a Mac, on Windows or on a phone?
All of them. There is nothing to install: any browser with WebGL 2 will do, which covers current Chrome, Edge, Firefox and Safari on desktop, and Safari and Chrome on mobile. A phone has less memory than a laptop, so a very heavy scene may be the one thing it cannot finish.
Related conversions
Other things to do with the same file.
From STP:
Other ways to get to PLY:
Or do something else with it: