Private browser-based STL inspection

Free STL Viewer Online

Open an STL, rotate it freely, and review its dimensions and triangle count.

Open an STL file

Drag and drop an STL file here

.stl only - maximum 25 MB

Viewed locally in your browser - your file is not uploaded.

How to use the STL Viewer

  1. Choose or drop an STL file.
  2. Rotate with drag, zoom with the wheel or pinch, and pan with right drag or two fingers.
  3. Review the model bounds and complexity.

What the Viewer shows

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.

FAQ

Does my STL file get uploaded?

No. Your file stays on your device while you view it.

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.

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.