3D printing · comparison
3MF vs STL: which should you use?
Both describe a printable shape. 3MF also remembers size, colour and how your plate was set up. Here's when that matters — and when plain STL is still the safer choice.
By the Kenerate AI teamUpdated 2 min read
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Quick answer
Updated
Use 3MF when your slicer supports it, because it stores units in millimetres, colours, materials, several objects and slicer settings, usually in a smaller file. Use STL when sharing with older tools, CAD imports or print services that only accept it: every program reads it, but it holds only triangles, with no units or colour.
Key facts
- Units
- 3MF: stored · STL: none
- Colour
- 3MF: yes · STL: no
- Multiple objects
- 3MF: yes · STL: one mesh
- File size
- 3MF usually smaller (ZIP, shared vertices)
- Compatibility
- STL: everything · 3MF: modern slicers
On this page
3MF vs STL
Side by side
| 3MF | STL | |
|---|---|---|
| Created | 3MF Consortium, 2015 [1] | 3D Systems, 1987 [2] |
| Structure | ZIP package with XML model [1] | List of triangles [2] |
| Units | Stored, millimetres by default [1] | None — slicers assume mm [2] |
| Colours, materials | Yes | No |
| Several objects | Yes, with positions and plates | One triangle soup |
| Slicer settings | Can be embedded | No |
| File size | Usually smaller | Larger for the same mesh |
| Opens in | Modern slicers, Windows 3D Builder | Everything |
When to choose 3MF
- Multi-colour or multi-material prints.
- Projects with several parts arranged on a plate.
- Sharing a print with its settings and supports.
- Avoiding scale mistakes — the unit travels with the file.
When STL is still better
- Print services and marketplaces that only accept STL.
- Older slicers, firmware tools and some CAD imports.
- Simple single-part prints where colour and settings don't matter.
Converting between them
STL → 3MF adds a unit and merges repeated vertices, so the file is usually smaller. 3MF → STL keeps the geometry but drops colours, plate layout and settings, because STL has nowhere to put them [2].
How it works
How it works in the app
Step 1
Choose text, photo or multi-view
Open 3D Studio and pick how to start: describe an object, upload a photo, or add several views.
Step 2
Pick a 3D engine
Open the model card to choose the engine and version that fits your object.
Step 3
Describe the object
Write one object on a plain background, then set textures, PBR materials and quality.
Step 4
Click Build 3D model
Press Build 3D model to start — the textured model appears in your gallery.
See it in the app
Open 3D Studio and pick how to start: describe an object, upload a photo, or add several views.
FAQ
3MF vs STL: questions
7 questions
Is 3MF better than STL?
For modern printing workflows, yes — it stores units, colours and multiple objects. STL wins on compatibility.
Link to this answerIs 3MF smaller than STL?
Usually. 3MF is compressed and shares vertices between triangles.
Link to this answerDoes print quality differ?
No — the geometry is the same. Differences come from settings, which 3MF can carry along.
Link to this answerCan every slicer open 3MF?
Major modern slicers can. Some older tools and services still need STL.
Link to this answerHow do I convert STL to 3MF?
Use the free STL to 3MF converter; set a size in millimetres if needed.
Link to this answerShould I download 3MF or STL files?
Take the 3MF when a model site offers both and your slicer reads it — you get the designer's units, colours, part layout and often their print settings. Take the STL for older slicers, CAD imports or print services that only accept STL; you'll set the size and settings yourself.
Link to this answerHow do I change 3MF to STL?
Drop the .3mf into the free 3MF to STL converter, check the preview and download a binary STL. The geometry is kept in millimetres; colours, plate layout and settings are dropped because STL can't hold them. Nothing is uploaded — the conversion runs in your browser.
Link to this answer