Does the number of triangles change?

No. In the tests, the count was the same.

And if the GLB has animation?

The STL stores a single pose, with no animation.

Open or drag the .glb file.
Check the “Size in the STL” in the conversion area and adjust the unit, if needed.
Click Convert and download.
Open the STL in the slicer and check the scale.

Many 3D model catalogs offer GLB.

STL is the slicers’ input format.

In GLB, the unit is usually meters: the app already suggests Meters.
If the part looks small in the slicer, check the unit before adjusting the scale there.

STL stores no colors or textures: only the shape. Colors from a scan are left out.
The app does not repair the model: it does not close holes, does not check whether the mesh is closed and does not trim parts. Scans usually have flaws, and the slicer (or a mesh editing program) may need to fix them.
The STL file does not store the unit. The app writes in millimeters, which is what most slicers expect, and shows the final size before downloading: check that it matches the real object.
Files of up to 400 MB. Everything is done in the browser, without sending the model.
The app converts and shows the model: it does not edit the mesh or the textures.

Does the number of triangles change?: No. In the tests, the count was the same.
And if the GLB has animation?: The STL stores a single pose, with no animation.

Text written by Marcelo Amantino · updated October 18, 2026 · who we are