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3MF to STL Converter: Free & Online
Convert 3D models from .3MF to .STL (Stereolithography) file format and prepare for printing in one app.
- Free
- No sign-up
- No install
Open .3mf → Export → choose .stl
Click Open Files and pick your .3mf file. Then click Export, choose .stl in the Extension list and click Save.
How to convert 3MF to STL
Open your .3mf file
Click Open Files in the converter above and pick the file on your computer. It opens in your browser, with no sign-up.
Export as .stl
Click Export and choose .stl in the Extension list. The list starts at .mrmesh, the native MeshInspector format.
Save the file
Click Save. The .stl file downloads to your computer.
In the desktop app
- Install and sign in. Download MeshInspector for Windows, macOS or Linux and sign in. The free Community plan is enough.
- Open the file. Click Open Files and pick the .3mf file.
- Export. Select the model, click Export and choose .stl.
- Save. Pick a folder and save the .stl file.
What to know about 3MF → STL
- 3MF is a ZIP package around an XML model. It records units, millimeters by default, and can hold several objects, colors and print settings.
- STL keeps only the triangles: colors, materials, object names and print settings stay behind in the 3MF.
- STL has no units and slicers read millimeters, so a 3MF modeled in inches needs a Scale after conversion.
- Export saves one object at a time. A 3MF with several parts opens as several objects: export them one by one, or combine them first in the desktop app.
- MeshInspector writes binary STL, the compact form of the format that slicers read.
Online or desktop
Online
The converter on this page runs the MeshInspector web app in your browser: no install, no sign-up. It suits single files; the web app works within your browser's memory.
Desktop
The desktop app runs on Windows, macOS (Apple silicon) and Linux. Use it for large files, many files, and the tools the web app does not have. The free Community plan covers opening and exporting; see Pricing for what the paid plans add.
FAQ
Do I need an account to convert 3MF to STL?
No. The converter on this page is the MeshInspector web app running in your browser without sign-up. Click Open Files and pick your .3mf file, select it in the scene list, click Export, choose .stl in the Extension list and click Save. The converted file downloads to your computer.
Is the 3MF to STL converter free?
Yes. Opening a .3mf file and exporting it as .stl use free tools, here, in the web app and in the desktop app on the free Community plan. Paid plans add tools such as Mesh Healer and automatic repair; the Pricing page lists what each plan includes.
Are colors and units kept?
STL keeps only the triangles: colors, textures and units are lost when you convert to STL. STL has no units, and most slicers read the numbers as millimeters, so check the size of the model after conversion and use Scale if it is off by a factor of 10, 25.4 or 1000.
Is there a file size limit?
There is no fixed limit on this page, but the web app works within your browser's memory: up to about 4 GB, or 16 GB in browsers with 64-bit WebAssembly. For very large models, or many files, use the desktop app for Windows, macOS or Linux.
Free Community planWindows, macOS (Apple silicon) and Linux
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By Mesh Inspector TeamPublished: Updated:
