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 and AMF models in an interactive WebGL viewer with triangle count, bounding box, surface area and volume. 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.
- 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.