STL → 3MF · FREE · NO UPLOAD
STL to 3MF Converter — Wrap Geometry for Slicers
Turn a .stl into a .3mf container for Bambu Studio, PrusaSlicer, OrcaSlicer and Cura — in the browser, nothing uploaded.
Wrapping a triangle mesh for slicers that want 3MF
An STL stores only triangles — no color, no units, no settings. 3MF is a ZIP-based package format (OPC) that can store the mesh plus print settings, materials, and plate layout in XML. Bambu Studio, PrusaSlicer, OrcaSlicer, and Cura all use 3MF as their default project format. Some slicers and print services prefer or require 3MF input. That is when you convert stl to 3mf.
This conversion wraps the STL geometry into a valid 3MF container. Geometry is preserved exactly. The output 3MF does not contain print settings, colors, or plate layout — those come from the slicer after import. Drop the file above, check the preview, and download 3MF (or OBJ, if the next tool prefers that). Processing is 100% client-side. There is no upload endpoint. The file never leaves the device.
Related: 3MF to STL for the reverse trip, what a 3MF file actually is for the format details.
STL vs 3MF at a glance
| STL | 3MF | |
|---|---|---|
| What it is | Raw triangle list — no color, no units, no settings | ZIP-based OPC package with mesh + print settings + materials + plate layout in XML |
| Colors & materials | No | Yes (in a full slicer project) |
| Print settings, supports, plate | No | Yes (slicer project) |
| Units | Undefined — slicers assume mm | Defined in the file (mm by default) |
| This converter writes | The source mesh | Geometry only — no settings, colors, or plate layout |
The 3MF format can hold a complete print project. This stl to 3mf converter only wraps the mesh. Open the download in your slicer to add settings, materials, and plate layout.
FAQ
Is my STL file uploaded to a server?+
No. Parsing the STL and wrapping it as 3MF both run in this tab with JavaScript. There is no upload endpoint — the file never leaves the device. The conversion works offline once the page has loaded.
Why convert STL to 3MF?+
3MF is the default project format for Bambu Studio, PrusaSlicer, OrcaSlicer, and Cura. Some slicers and print services prefer or require 3MF input. The format can carry print settings, materials, and plate layout — those extras are added by the slicer after you import, not by this converter.
What is added that STL doesn't have?+
Nothing by this tool. STL stores only triangles — no color, no units, no settings. The converter wraps that geometry in a valid 3MF container (a ZIP-based OPC package with the mesh in XML). The wrapper is minimal. Print settings, colors, materials, and plate layout are not added here; the slicer fills those in on import.
Does the 3MF include print settings?+
No. This converter wraps geometry only. The output 3MF does not contain print settings, colors, or plate layout. Import the file into Bambu Studio, PrusaSlicer, OrcaSlicer, or Cura to add those.
Can I convert 3MF back to STL?+
Yes. Use the 3MF to STL page on this site. That conversion extracts the mesh and drops any project metadata the 3MF may have picked up in a slicer.
Is the mesh modified during conversion?+
No. Vertices and triangles are preserved exactly. The same geometry that was in the STL is written into the 3MF mesh XML.