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.

Why use 3MF instead of STL?

3MF files are zipped, so they're usually smaller. They store the unit (mm), and they can hold many parts in one file.

No. You get the shapes only. Set colours and settings in your slicer, then save the project from there.

All tools / STL to 3MF

Turn one STL, or a whole set of them, into a single 3MF. It's smaller, it records the units, and every slicer opens it.

Good to know

	STL	3MF
Unit	Not stored	Stored (we write millimetres)
Many parts in one file	No	Yes, each stays separate
File size	Larger: every triangle repeats its corners	Smaller: shared corners, zipped
Colours, settings	No	Possible, added by your slicer

For sharing a set of parts, one 3MF beats a folder of STLs.

Each STL you drop becomes its own object, in the same layout you see in the preview.
We don't add print settings or colours. Set those in your slicer and save the project from there.
Bambu Studio, PrusaSlicer, OrcaSlicer and Cura all open 3MF.

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.
Why use 3MF instead of STL?: 3MF files are zipped, so they're usually smaller. They store the unit (mm), and they can hold many parts in one file.
Does it add print settings or colours?: No. You get the shapes only. Set colours and settings in your slicer, then save the project from there.