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GLBKit

STL to PLY Converter

Convert an STL to ASCII PLY with positions and vertex normals, for Open3D, PCL and other geometry libraries. Runs in your browser.

Drag & drop your STL file here

or click to browse

Supported Formats

.glb.gltf.obj.fbx.stl.ply.3mf.off.zip

Format Information

Source Format

STL.stl

STL (Stereolithography)

STL is an additive-manufacturing format from the 1990s: a flat list of triangles and nothing else. It has no concept of a scene, a material or a texture, which is why it is the lingua franca of 3D printing and also its most lossy interchange format.

What it carries: Triangle positions and, optionally, one facet normal per triangle. No UVs, no vertex colours, no materials, no node hierarchy, no animation.

Open a STL file in the viewer

Target Format

PLY.ply

PLY (Polygon File Format)

PLY is a flexible text or binary format that can describe either a polygon mesh or a bare point cloud, depending on whether the file declares a face element alongside its vertices. That dual nature is why PLY appears in both modelling and LiDAR workflows.

What it carries: Per-vertex position, optional normals, optional RGB colours, optional UVs on mesh PLY files, and face indices. Image textures, material graphs and animation are not part of the format.

Open a PLY file in the viewer

About this conversion

The move from a print format to a data format. The triangles are written into an ASCII PLY 1.0 file, which is the input most geometry-processing libraries expect.

Why convert STL to PLY

  • Load the shape into Open3D, PCL, trimesh or a geometry-processing library.
  • Run analysis or cleanup on a print file in a scientific toolchain.
  • Produce a text mesh your own scripts can open, edit and re-export without a 3D library.

What happens during the conversion

Geometry

The triangle list is written as one PLY vertex list and face list, with the STL's facet normals carried across as vertex normals. Everything ends up in a single mesh, since STL has no hierarchy.

Materials and textures

None to transfer. PLY is written with geometry and normals; the source has no colour or texture data.

Common use cases

  • Repairing or analysing a scanned or printed part in a geometry library that needs a PLY rather than an STL.
  • Feeding a print file into a mesh-processing pipeline.
  • Turning a printer file into a mesh your own scripts can read and edit directly.

Limitations of this conversion

  • No colour, no texture and no UVs — the source has none of them either.
  • The PLY is ASCII, so the file is much larger than the binary STL it was made from, and it carries normals rather than one facet normal per triangle.
  • STL has no unit metadata, so scale must be confirmed downstream.

How to convert STL to PLY

Three steps in the browser. Nothing is uploaded to a server, so an unwieldy file is limited only by your own device's memory.

1
STEP 1

Upload your .stl

Binary and ASCII STL are both supported, and the file's facet normals become the mesh normals in the PLY.

2
STEP 2

Convert to PLY

Triangles and the file's facet normals are written into an ASCII PLY 1.0 file.

3
STEP 3

Load the .ply in your processing library

Confirm the scale, since STL carries no unit information.

Related tools and formats

Frequently Asked Questions

Questions people ask when turning STL files into PLY.

Looking for a different direction? See every supported conversion.