Will the converted OBJ open in Blender without issues?

Yes — File → Import → Wavefront (.obj) and you're done. Since STL carries no units, Blender reads it in meters: if the part looks huge, apply a 0.001 factor on import or scale afterwards.

Is a .mtl materials file generated?

No, because an STL has no materials to export: the OBJ comes out as pure geometry. Every program opens it fine without the .mtl — it simply applies a default material.

Is the mesh just as precise?

Identical: every STL triangle goes into the OBJ with the same coordinates. The only internal difference is that OBJ shares vertices between neighboring triangles, which usually makes the file lighter without changing the shape.

No file handy?

Convert toOBJ

Coordinates and scale are preserved exactly as they are.

Convert STL to OBJ

Drop your STL files and download them as OBJ: free, in batch, and they never leave your device.

STL → OBJ: what you should know

STL and OBJ are the two veteran 3D formats, but they speak different dialects: STL describes a part as a soup of unconnected triangles, while OBJ organizes the mesh with shared vertices and can carry groups, smoothed normals and material references. Converting STL to OBJ is the typical step when a part meant for printing needs to enter Blender, Maya or a game engine.

The conversion here is direct and surprise-free: triangles are copied with their exact coordinates — nothing is rescaled, nothing is recentered, so your millimeter-calibrated part still measures the same. Everything happens in your browser: the file is never uploaded to a server, which also makes it safe for confidential client parts.

Since STL stores no colors or textures, the resulting OBJ is pure geometry — exactly what you need for retopology, sculpting or scene integration. If your workflow goes the other way (taking a DCC model to the printer), check the OBJ to STL converter.

Related conversions

STL → PLY STL → GLB STL → USDZ STL → 3MF PLY → OBJ glTF → OBJ GLB → OBJ 3MF → OBJ

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