STL vs PLY
Both store raw geometry with no units. STL holds triangles only and is the language of slicers. PLY can also store per-vertex colour, normals and point clouds, which is why 3D scanners and tools like MeshLab and CloudCompare export it. For printing, STL is the expected format; for scans and coloured meshes, PLY keeps information STL throws away.
Side by side
| STL | PLY | |
|---|---|---|
| Full name | stereolithography mesh | Polygon File Format |
| Created by | 3D Systems | Stanford University |
| Introduced | 1987 | 1994 |
| Encoding | binary or ASCII | binary or ASCII |
| File size | compact in binary; repeats every shared vertex | compact in binary |
| Materials | No | No |
| Textures | No | No |
| Animation | No | No |
| Colour | no colour or materials | per-vertex colour |
| Units | unitless (slicers assume millimetres) | unitless |
| Best for | 3D printing slicers | 3D scans, point clouds and research tools like MeshLab and CloudCompare |
Choose STL when
- •You're printing the model.
- •A print service or slicer asks for STL.
- •Colour doesn't matter, only the shape.
Choose PLY when
- •The data comes from a 3D scanner or photogrammetry.
- •You need per-vertex colour or a point cloud.
- •You're processing the mesh in MeshLab or CloudCompare.
Which apps open them
Of the 15 3D apps in our software guides, 9 open STL without conversion and 4 open PLY. Only STL opens directly in 3ds Max, Bambu Studio, OrcaSlicer, PrusaSlicer, UltiMaker Cura.
Questions
- Is STL better than PLY?
- Neither is better everywhere. You're printing the model: choose STL. The data comes from a 3D scanner or photogrammetry: choose PLY.
- Can I convert STL to PLY?
- Yes. Our STL to PLY converter runs in your browser. The shape and supported materials carry over.
- Which file is smaller, STL or PLY?
- STL: compact in binary; repeats every shared vertex. PLY: compact in binary. Actual size depends mostly on polygon count and texture resolution.
Written with AI assistance by the Renderlyst team in October 2026. Format support reflects each app's current release as we understand it, and we link the official documentation so you can confirm it for your version. Spotted something out of date? Email alishbakhalid766@gmail.com.