Inspect an export before releasing it
- Confirm the intended revision and all visible required parts.
- Establish the coordinate unit from a source reference.
- Inspect a curve silhouette and a named opening or contact face. The changed-square-hole and curve controls are available in the existing example selector.
- Choose supported topology checking or revision review for the remaining question.
Rotate by dragging, zoom with the wheel or pinch, and pan with right drag or two fingers. With the intended unit selected, Measure distance picks two visible mesh points. Inspect cross-section moves a display cut through the model; it does not alter the saved file.
What the Viewer shows
Try the owned curved control linked below: with a millimetre assumption, its overall bounds are 20 x 20 x 10 mm, but a vertical side edge spans only 10 mm. Two picked mesh points answer a different question from the full bounding box. The small recessed key also shows why a rounded silhouette and matching outer size cannot establish that all detail survived.
The viewer calculates the model's bounding dimensions and triangle count directly from its geometry. STL coordinates have no native unit, so confirm scale in your slicer.
Bounding dimensions describe the full model. Point-to-point measurement checks two selected features, such as an opening width or mounting-tab length. Read how to measure a 3D model for a practical workflow.
Inspect a cross-section
On that 10 mm-high control, a Z cut at 5 mm hides one half of the displayed solid. Rotate the view to inspect the exposed boundary. The display does not add a measured cap or calculate a section area; the original file stays unchanged. A clipped-open view is not an open-edge finding in the stored mesh.
Choose Inspect cross-section below the viewer, choose an X, Y or Z cut axis, then move the cut position through the displayed model. It hides one side of the mesh so you can inspect internal geometry from different angles. Read how to inspect STL and 3MF cross-sections for a careful workflow and its limits.
Locate mesh issues
Open edges can mean gaps in a surface, while non-manifold edges can confuse slicers. Highlighting is diagnostic: it shows reported locations but does not repair the model. Use the STL Quality Checker, STL Watertight Checker, STL Manifold Checker, or guide to fixing non-manifold STL files for the next step.
FAQ
Does my STL file get uploaded?
Viewing is local. If you explicitly request Locate mesh issues, the file is uploaded for server analysis through the Quality Checker.
Can I view ASCII and binary STL files?
Yes, both common STL encodings are supported.
Why do STL dimensions not specify mm or inches?
STL stores coordinates but not a unit system.
How accurate is the measurement tool?
It measures points on the displayed mesh. Results depend on mesh resolution, selected points and your chosen unit; use CAD or calibrated physical measurement for tighter tolerances.
Does viewing an STL check whether it is printable?
No. It is a visual inspection tool, not a mesh validation service.
What should I use to check for holes or non-manifold geometry?
Use the Quality Checker and Watertight Checker.