AMF File Format (.amf)
An AMF file holds a 3D-printable object description in XML, adding curved triangles, per-vertex colour, multiple materials and lattice structures beyond what STL's flat triangle mesh can record.
AMF at a glance#
| Full name | Additive Manufacturing File Format |
|---|---|
| File extension | .amf |
| Category | 3D Models |
| Developer | ASTM International |
| First released | 2011 |
| Compression | Lossless |
| Specification | ISO/ASTM 52915 |
| FileFlip support | FileFlip reads this format but does not write it |
What a .amf file can hold#
These are the things a AMF file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Embedded metadata | Yes |
|---|---|
| Textures and materials | Yes |
Strengths and limitations of AMF#
What AMF does well
- Curved triangles cut faceting error on spherical and cylindrical surfaces without adding polygon count
- Carries colour, multiple materials and lattice structures that plain STL has no fields for at all
- XML text compresses well, often landing near half the size of an equivalent zipped STL
Where AMF falls short
- 3MF is what the 3D printing industry actually standardised on, so slicer support for AMF is patchy
- Few current consumer slicers ship an AMF importer any more; Ultimaker Cura is one of the few that still does
Use AMF when a tool specifically outputs it and needs to carry colour or multi-material data that STL can't hold.
Convert AMF to 3MF or STL for any modern slicer, since that's what current 3D printing software actually expects.
How to open a .amf file#
A .amf file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts AMF into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Ultimaker Cura |
| macOS | Ultimaker Cura |
| Linux | Ultimaker Cura |
| Web | FileFlip |
AMF questions people ask#
What is an AMF file used for?
AMF is a 3D printing format meant to describe an object's colour, materials and curved surfaces alongside its geometry, which is more than STL, the format it was designed to replace, can store.
Is AMF better than STL?
AMF stores more than STL, including colour, multiple materials, curved triangles and units, all things a bare STL file has no field for. That richer feature set never translated into wide slicer support, so most workflows still default to STL or 3MF.
Why did 3MF replace AMF?
3MF launched in 2015 with backing from major CAD and printer vendors and a simpler, ZIP-based structure, and it picked up the slicer and printer support that AMF, despite arriving first with similar goals, never got.
Converting AMF files#
Convert AMF to another format
FileFlip does not write .amf files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.