Fast local print-mesh inspector

Free Online STL Viewer

Open a .stl model directly on this device to inspect its printable surface, orientation and triangle count before slicing, repairing or converting it.

Try a local STL sample

Choose a classic model to test the viewer before opening your own file.

Sample models from the public common-3d-test-models repository.

What this STL viewer checks

STL represents a model as a triangle surface and is the most common handoff format for 3D printing. It is simple and widely supported, but it does not define scene hierarchy, materials, textures or a reliable unit system.

  1. 01 Choose or drop a .stl file.
  2. 02 Let the local parser read its triangle geometry.
  3. 03 Rotate, zoom and inspect vertices, faces and mesh count.

STL compatibility

Feature Status What to expect
Binary STL Supported Compact triangle geometry renders locally
ASCII STL Supported Text-based triangle geometry renders locally
Surface normals Supported Recomputed for consistent shading
Units Not defined Confirm scale in your slicer or CAD application
Materials and textures Not available STL stores triangle surfaces only

Private local processing

The browser reads the selected bytes and sends them straight to the local parser and 3D renderer. There is no model upload endpoint, account, storage bucket or server-side processing step.

Limits to know

The viewer can inspect binary and ASCII STL geometry, but STL does not record authoritative units, color, materials, textures or assembly structure. Confirm dimensions and print settings in your slicer before manufacturing.

Convert or inspect another format

STL to OBJ Move STL geometry into a broadly editable mesh format. STL to GLB Package the mesh in a compact web-native container. STL to glTF Export the triangle mesh to an inspectable web format.

Frequently asked questions

Is my STL file uploaded?

No. The file is read and rendered only inside your browser tab.

Does the viewer support binary and ASCII STL?

Yes. The local loader detects and reads both common STL encodings.

Why does the viewer not show STL units or colors?

Standard STL stores triangle geometry without authoritative units, materials or textures. The viewer uses neutral shading and reports geometry counts.

Can I convert STL after checking it?

Yes. Use the related STL to OBJ, GLB or glTF converters; every route runs locally in the browser.