Convert STL to 3MF online — free, no signup, no upload
STL is the classic triangle mesh; 3MF is the newer 3D-printing format that carries units and is less error-prone. Converting STL→3MF packages the same geometry into a modern container. This converter runs entirely in your browser: your file is read on your device, converted, and downloaded — it is never uploaded to a server.
How to convert STL to 3MF
1. Drag your file onto the box above, or click Open STL file. 2. Preview the model in 3D to confirm it's the right one. 3. Click Convert to 3MF & download — the new file saves straight to your device.
Frequently asked questions
How do I convert STL to 3MF?
Drop your .stl above or click Open, preview it, then click Convert to 3MF & download. It runs entirely in your browser.
Why convert STL to 3MF?
3MF is a modern, ZIP-based format that stores real-world units and is supported by newer slicers like PrusaSlicer, Bambu Studio and Cura.
Is my STL uploaded?
No. The conversion happens fully on your device.