Do my files get uploaded?

No. Everything runs in your browser. The file never leaves your computer, so it works for client files and unreleased designs too.

What gets lost going from 3MF to STL?

Colours, filament choices, print settings and plate layout. STL only stores the shape. The geometry itself comes across exactly.

They're merged into one STL in the same positions. If you need them as separate files, open the 3MF in your slicer and export each one.

All tools / 3MF to STL

Got a 3MF from MakerWorld or Printables but your tool wants STL? Drop it here and get an STL back at the right size.

Good to know

	In the 3MF	In your STL
Shape	Yes	Yes, exactly the same triangles
Size	Stored with a unit	Numbers in mm (STL has no unit; slicers assume mm)
Several parts	Kept separate	Merged into one mesh, in the same spots
Colours and filaments	Yes	No
Print settings and plates	Often, in slicer projects	No

STL keeps the shape and drops everything else. If you need the settings, keep the 3MF too.

A print service, an older tool or a friend's setup only takes STL.
You want to edit the shape in an app that doesn't open 3MF.
You only need one part of a multi-part project: open the 3MF in your slicer and export that one object as STL instead.

If the file was saved in inches, the size will look 25 times too small. Pick Inches under File units.

1Drop your 3MF in the box. Files from MakerWorld, Printables and Bambu Studio all work.
2If it holds several parts, they come out merged, in the same spots. Check the size in mm.
3Click Download STL.

Checked October 2026

Do my files get uploaded?: No. Everything runs in your browser. The file never leaves your computer, so it works for client files and unreleased designs too.
What gets lost going from 3MF to STL?: Colours, filament choices, print settings and plate layout. STL only stores the shape. The geometry itself comes across exactly.
My 3MF has several parts. What happens?: They're merged into one STL in the same positions. If you need them as separate files, open the 3MF in your slicer and export each one.