For Bambu Studio, OrcaSlicer and PrusaSlicer project files
3MF to STL Converter, Free and Private
Drop a 3MF and get an STL: everything on the plate in one file, or one STL per object or per part in a ZIP. Bambu Studio and OrcaSlicer projects that keep each object in its own file are read too. It runs in your browser: nothing is uploaded and nothing is charged.
What the Converter Does With Your 3MF
- 1Opens the 3MF package and follows every reference, including the Production extension that Bambu Studio and OrcaSlicer use to keep each object in its own file under 3D/Objects.
- 2Places each object where it sits on the plate: build and component transforms are applied, and a mirrored part keeps its faces pointing outward.
- 3Converts the unit of the 3MF (micron, millimeter, centimeter, inch, foot or meter) to millimeters, the unit slicers assume for an STL.
- 4Leaves out what does not print: modifiers, negative parts, support blockers and enforcers set in Bambu Studio, OrcaSlicer or PrusaSlicer, support objects and objects set to not printable. It tells you how many.
- 5Writes binary STL: one file for everything, or a ZIP with one STL per object or one per part, named after the objects and parts of your project.
- 6Checks every file it writes: triangle count, size in mm, and whether each mesh is watertight. Nothing is repaired or simplified.
What an STL Cannot Carry
An STL is only triangles. Three things in your 3MF stay behind, and the converter says so.
Colors
Painted colors, color groups and filament numbers are lost: an STL has no color. If the colors of your model are separate parts, choose One STL per part: each part arrives as its own file, all in the same position.
Print settings
Layer height, infill, supports and the printer profile live in the project, not in the mesh. Set them again in the slicer you open the STL in.
Sliced files
A .gcode.3mf holds the G-code of a sliced plate, not an editable project. The converter refuses it: convert the project 3MF, the file you open and edit in the slicer.
Why Convert a 3MF to STL?
A 3MF carries far more than an STL: units, parts, colors, plates and print settings, in a compressed package. But some modeling apps, online print services and resin slicers still take STL only, and an STL opens everywhere. The catch is getting the geometry out without the extras that do not print: a modifier box or a negative part merged into the STL would come out as solid plastic. Here they are left out, and counted.
3MF to STL Questions
Is the 3MF to STL converter really free?
Yes. A 3MF already holds a mesh, so there is nothing to trace: the STL is written in your browser, with no account, no watermark and no limit. What VectoSolve charges for is turning a picture (PNG, JPG) into a clean vector.
Is my 3MF uploaded anywhere?
No. The file is read and converted in your browser tab. Close the page and it is gone.
Does it work with Bambu Studio and MakerWorld project files?
Yes. Bambu Studio and OrcaSlicer keep each object in its own file inside the 3MF (the Production extension of the format). The converter follows those references and applies every transform. It was checked on project files written by OrcaSlicer itself, including a 39-part multicolor badge.
What happens to modifiers and negative parts?
They are left out, and the converter tells you how many. A modifier is a volume that changes print settings inside it, not plastic: merged into an STL, it would print as a solid block. Support blockers and enforcers are left out for the same reason.
Are the colors kept?
No, an STL has no color. If the colors of your model are separate parts, choose One STL per part: you get one file per part, all in the same position, so they line up again when you load them together. Colors painted onto a single part cannot be split into files.
My project has several plates. What do I get?
Every object on every plate is converted, at its position in the project. Choose One STL per object to get each object as its own file, whatever plate it sits on.
What unit is the STL in?
Millimeters. A 3MF declares its unit and the converter turns it into millimeters, which is what slicers read in an STL. A 3MF in inches gives an STL in millimeters at the same physical size.
Will my STL be watertight?
It is exactly as watertight as the mesh in your 3MF: the converter keeps the triangles as they are and checks them. Each file shows its triangle count, its size in mm and whether it is watertight. Nothing is repaired or simplified.
Is there a size limit?
Up to 100 MB per 3MF. The limit is the memory of a browser tab, not a quota.
Convert your 3MF to STL now
Free, in your browser, no signup.
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