STL
Extensions: stl22 tools
STL is the de facto standard mesh format in 3D printing, storing only triangular surface data since 1987, without color, texture, or material. Almost all slicers (Cura, PrusaSlicer, Bambu Studio, ChiTuBox) and printers directly support STL, ensuring its enduring popularity.
Two classic pitfalls: STL lacks unit definitions, making millimeters and inches indistinguishable on disk; always verify scale in your slicer. It also has ASCII (readable but 4-6x larger) and binary (compact, default) encodings. For multi-color printing, materials, or parameters, switch to 3MF, which carries richer print information while maintaining slicer compatibility.
Format Details
- Full Name
- Stereolithography
- Type
- 3D Mesh
- Open With
- Slicer SoftwareWindows 3D Viewer
- Notes
- Does not support colors, textures or materials
- No unit definition; verify scale in your slicer
- ASCII format is 4-6× larger than binary
- Supported Features
- Triangle mesh only, simple and universally compatible
- Binary and ASCII encoding options
- Directly importable into Cura, PrusaSlicer, Chitubox, etc.

