All tools

STL Viewer & Analyzer

Inspect an STL before you slice. Load a binary or ASCII file on this device to review bounding-box size and triangle count. Approximate volume and surface area appear only when the mesh supports a reliable calculation.

Local only

STL Viewer & Analyzer

Load an STL on this device. The model is placed on the build plate (grid). Drag to rotate, scroll to zoom, or use the move / view controls.

No file loaded. Max size 40 MB (ASCII or binary STL).

  • Triangles —
  • Size (X × Y × Z) —

How to use it

  1. Choose an STL file (or use the sample if offered). The model stays in your browser.
  2. Orbit, zoom, and pan to inspect the shape; use move/rotate controls when you need precise placement on the plate.
  3. Read dimensions and triangle count. Treat volume/surface as approximate only when shown.
  4. Clear the viewer when finished — nothing was uploaded to the server.

Formula

Bounding box = axis-aligned extents in millimetres. Triangle count = number of facets in the mesh. Volume/surface use a signed-volume method and are shown only when the result looks reliable for a closed mesh.

Example

Example workflow: load a client STL, confirm units look like millimetres (not accidental centimetres), note triangle density, then take the size into your slicer and cost tools.

Assumptions and limitations

  • Files are processed locally in the browser and are not uploaded to RB3DLabs.
  • Very large files may be rejected by the tool’s size limit for performance.
  • Open or non-manifold meshes may hide volume/surface estimates on purpose.
  • This viewer does not replace slicer checks for overhangs, wall thickness, or printability.

Frequently asked questions

Is my STL uploaded?

No. The file is read with the browser File API and stays on your device.

Why is volume missing?

Volume and surface area are shown only when the mesh metrics look reliable. Open meshes and bad normals often fail that check.

ASCII and binary STL both work?

Yes. Both common STL encodings are supported.