Question 1

What is the difference between STL, 3MF, and OBJ?

Accepted Answer

STL stores only raw triangle geometry — no color, materials, units, or scale, and vertices are duplicated per triangle. OBJ stores geometry with optional normals and UV coordinates, and can reference a separate .mtl file for materials. 3MF is a modern ZIP+XML format that stores indexed geometry along with units, color, and multi-object scenes in one file — the default export format in most current slicers (Bambu Studio, PrusaSlicer, Orca Slicer).

Question 2

Which format should I use for 3D printing?

Accepted Answer

For single-color, single-part models, STL remains the most universally compatible format. If you need multiple colors, multiple parts, or reliable scale, 3MF is the better choice. OBJ is mainly useful for moving a model between 3D modeling tools (e.g. Blender), not for slicing.

Question 3

Will converting between formats lose any data?

Accepted Answer

This converter works at the geometry level only — it preserves shape, dimensions, and triangle count exactly, but does not preserve color, materials, or textures, since STL cannot represent any of these (any conversion involving STL is always geometry-only).

Question 4

Is my file uploaded to a server?

Accepted Answer

No. Conversion happens entirely in your browser — the file is never uploaded. This also means very large files may take longer on slower devices.

STL / 3MF / OBJ / BLEND Converter

FAQ