3MF & STL conversion tools

Convert STL to 3MF Online

Upload an ASCII or binary STL, choose its source units, and download a 3MF model. Preserve the existing mesh and store its dimensions in millimeters.

Reverse conversion: 3MF → STL

STL → 3MFLocal processing

Model files are processed in your browser and are not uploaded to a server.

STL source units

Use the units from the application that created the STL. They cannot be detected from the file.

STL contains no standard units or material information. Choose the original units before converting. The 3MF stores geometry in millimeters; it does not recover colors, filament slots or printer settings.

Your model preview will appear here after a valid file is converted.

Model files are processed in your browser and are not uploaded to a server.

What happens to your model?

Keep the existing geometry

Mesh vertices and assembly placements are carried into the output. Conversion does not remesh, repair holes or reconstruct missing surfaces.

Keep physical dimensions explicit

3MF units are converted to millimeters. For STL input, select the original units. The exported STL must also be imported as millimeters.

Understand format limits

Supports mesh-based core 3MF assemblies, Production Extension model references, and ASCII or binary STL. Unsupported required extensions are reported.

From model file to download

01
Choose your source file
Select or drop a model up to 25 MB. For STL, set the source units used by your design application.
02
Check the preview and dimensions
Review the mesh, triangle count and dimensions. Invalid references or unsupported geometry stop the conversion with an explanation.
03
Download and inspect in your slicer
Save the converted file, check its scale in your slicer and configure printing settings there. No automatic mesh repair is applied.

Frequently Asked Questions

File support, units and the information each format can preserve.

STL stores triangle geometry. Color, material, texture and slicer metadata are discarded. Printable mesh instances and their transformations become triangles in one binary STL file.