Convert STL to PLY
Convert STL to PLY in your browser. The conversion runs on this page and the file never leaves your computer.
Result
Before you convert: what this keeps and what it destroys
Preserved
- The geometry, triangle for triangle
- Overall dimensions and proportions
- Watertightness, where the input is watertight
Destroyed
- A recorded unit: PLY stores none
↺ the reverse: PLY → STL · about .stl · about .ply · just view it instead
Why people convert STL to PLY
Moving a print mesh into the tools that measure and repair meshes. PLY is what MeshLab and CloudCompare work in, so this is the usual first step before a decimation, a deviation check or a repair.
The geometry transfers exactly, since both formats are plain triangle meshes with no unit, and nothing is scaled or approximated.
PLY's headline feature, per-vertex colour with no sidecar file, has nothing to work with here, because an STL has no colour to give it. What PLY does add is a header that describes its own data, so any extra per-vertex property a tool wants to attach later has somewhere to live.
What you get
You get a binary PLY file containing the same triangles the STL file described. No geometry is added, removed or approximated: mesh-to-mesh conversion is a change of container, and this site's tests check that the triangle count comes out identical.
Not carried across by this conversion: a recorded unit.
The conversion runs in your browser. Your file stays on your computer and is not uploaded.
What to check afterwards
- STL carries no unit. The numbers in the file are just numbers, so the conversion assumes millimetres. Check the overall dimensions of the result before you commit to machining or printing it. A file exported from a package set to inches will be 25.4 times out.
- Coordinates are stored as 32-bit floats. For a part measured in millimetres that's far finer than any machine tolerance. For a model spanning hundreds of thousands of units it isn't.
If you need something this conversion cannot give you
If the unit has to be unambiguous, convert to 3MF instead. It records the unit in the file, so nobody downstream has to assume millimetres and nobody has to scale by 25.4 after the fact.
Going the other way
Convert PLY back to STL. The reverse conversion also works with mesh geometry. It does not reconstruct exact CAD surfaces. Material data and part structure lost in either direction cannot be restored by converting back. Keep the original file for later edits.
How we know this conversion works
This pair was checked against 9 files from the test corpus on 2026-09-04. Each run parses its own output back in and compares the bounding box, the triangle count and, for closed solids, the volume against the input.
A pair that fails those checks doesn't get a page. That's why this site lists 120 conversions and not the several hundred a format-times-format grid would suggest.