What is a .STL file?
STL is the most common 3D-printing mesh format, storing a model’s surface as triangles. Exported by most CAD tools and read by every slicer.
- Did you know
- STL was created by 3D Systems in 1987 for the first stereolithography 3D printers - hence the name.
- Although tied to stereolithography, STL is also expanded as “Standard Tessellation Language” or “Standard Triangle Language”.
- An STL file records only a surface as a list of triangles, each with three vertices and a normal vector, and carries no colour, texture or units.
- STL comes in two flavours: a verbose human-readable ASCII form and a far more compact binary form that most software prefers.
- Every 3D-printer slicer reads STL to convert a model into machine instructions, which is why it remains the lingua franca of desktop 3D printing.
- What Analyser shows you
- View STL, OBJ, PLY, OFF, STEP, IGES, BREP, 3MF, AMF and glTF/GLB models in an interactive WebGL viewer with orbit, orthographic or perspective projection, a wireframe topology overlay, an orientation cube, triangle count, bounding box, surface area and volume. glTF 2.0 and binary GLB scenes are parsed natively - the node graph is flattened, mesh geometry shown, and the authoring tool, version and mesh/material/animation counts read. STEP/IGES/BREP are tessellated with OpenCASCADE and STEP shows its originating CAD system, version and AP203/214/242 protocol; 3MF and AMF let you inspect each model and assembly on the build plate individually. Wavefront material libraries (MTL) are broken out into each material with its colours, shininess, opacity and the texture files it references.
- Open a .STL file
- Drag a .STL file onto the Analyser home page (or tap to pick one). It opens entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.