/ stl / viewer
STL viewer
Open a .stl file and see it, with its size, triangle count and mesh checks. STL stores no unit, so the size assumes millimetres. It renders in this tab.
Your file never leaves your browser. STEP, IGES and BREP fetch the OpenCASCADE kernel (2.3 MB over the wire); 3DM fetches rhino3dm (2.5 MB before compression); every mesh and scene format fetches neither. Nothing downloads until you pick a file.what we bundle ↗
estimate · above the measured floor
This will take about
Your file is . STEP parsing measured at across real CAD files, and this machine benchmarked . Nothing has been downloaded yet.
- Kernel to download — OpenCASCADE
- —
- Parse and tessellate
nobody should wait that long without having been told
above 25 MB · may not fit in a browser
This file may be too big for a browser
At this needs roughly here. Whether it fits depends on the geometry, not the size: a large CAD assembly can open, while a much smaller STEP exported from a mesh can run out of memory. If it does, this page says so, and the file never leaves your computer either way.
If it does not open here
- Bambu Studiofree · windows · macos · linux
- Blenderfree · windows · macos · linux
- FreeCADfree · windows · macos · linux
the same sourced table as the format page — dated, not invented
we never block the attempt, we only tell you the cost first
rendered locally · — fps
drag to orbit · scroll to zoom · shift-drag to pan
Check an STL before printing
Compare the displayed dimensions with a measurement you know. This viewer assumes millimetres because STL has no unit declaration. A part intended to be one inch long may appear as 1 mm if its export used inch coordinates.
Watertightness tells you whether the triangle edges form a closed, consistently oriented surface under this check. It does not certify wall thickness, clearances or printability. Inspect the sliced layers before printing.
An open-edge or winding warning needs investigation in the source model or a mesh editor. This viewer diagnoses those problems; it does not repair the mesh. The STL format guide explains why they occur.