Convert 3MF to STL
for Cura, in a few seconds
UltiMaker Cura slices STL natively. When your download ships as 3MF, 3mftostl.site flattens it into a clean, Cura-ready STL right in your browser — no upload, no account, no waiting on a server.
Drop .3mf files here
or drag & drop — up to 150 MB each, multiple files supported
Why Cura users flatten 3MF to STL
Cura opens 3MF too, but STL is still the safest common denominator across slicers, repair tools and print farms. Here is when a Cura-ready STL is the better pick.
Smaller, simpler files
Binary STL drops the textures, thumbnails and metadata that 3MF carries, so Cura loads the mesh faster and the project stays portable.
One mesh, no surprises
STL bakes every part into a single triangle soup. That is exactly what most downstream tools expect, with no build-tree ambiguity.
Repair-friendly
Mesh fixers (Netfabb, Microsoft 3D Builder, PrusaSlicer) ingest STL first. Flatten early and you can repair before Cura ever sees it.
Shareable everywhere
Send one STL to a friend, a print service or a different slicer without wondering whether their software reads 3MF the same way.
Turn a 3MF into a Cura-ready STL
- 1
Drop the .3mf
Drag your 3MF onto the converter above, or browse for it. Multi-part builds are welcome.
- 2
Pick binary STL
Cura expects binary STL. It is compact and loads instantly — leave ASCII for the rare tool that asks for plain text.
- 3
Download and slice
Save the STL and open it in Cura. Assemblies keep their transforms, so parts line up the way the designer intended.
Cura-specific tips
Binary or ASCII STL for Cura?
Binary. Cura reads both, but binary files are far smaller and parse faster. Use ASCII only if a specific pipeline demands text.
Will my multi-part 3MF stay aligned?
Yes. 3mftostl.site resolves the full build tree — nested components and per-item 4×4 transforms — so a multi-object model flattens into correctly placed triangles.
Units and scale — will they survive?
STL has no units, so Cura treats one unit as one millimeter by default. Your 3MF's coordinates are preserved 1:1, so size is unchanged; just confirm Cura's scene scale if a model looks off.
My 3MF is over 150 MB — what now?
The converter rejects files above 150 MB to keep the tab responsive. Split very large builds into smaller 3MF exports, then convert each part.
Back to the converter
Ready to flatten a model? Use the 3MF to STL converter on the home page, or just drop a file into the box above.