FILE FORMAT GUIDE
3MF File (.3MF): Package Structure & Inspection
A 3MF file is an Open Packaging Conventions package containing a 3D manufacturing payload. The standard supports a core mesh model and separately defined extensions.
Check supported header evidence locally. Identification is not file validation or a malware scan.
Analyze a file locallyQuick facts
- Extension
- .3mf
- Format
- 3D Manufacturing Format
- Category
- 3d
- MIME type
- model/3mf
- Standard / developer
- 3MF Consortium / ISO/IEC JTC 1
- Open with
- lib3mf
What is 3MF?
3MF packages model parts and relationships rather than storing only a triangle stream. Extension declarations matter: a consumer must understand required extensions before it can claim full-fidelity processing.
- Transfer 3D models and manufacturing information between design, service and printing systems
How to open 3MF
lib3mf is an implementation SDK, not a desktop viewer. Reading a package does not guarantee manufacturing fitness or safe extraction of arbitrary members.
lib3mfCross-platform SDK
Load the SDK, create a model and use QueryReader("3mf") to read the package, then inspect warnings and model resources. Do not assume unknown required extensions can be ignored.
Technical details
- Signature
- Not reviewed
- Encoding
- Not applicable
- Container
- Open Packaging Conventions ZIP package
- Compression
- ZIP package compression
Things to check
- Support for Core does not imply support for every materials, production, secure-content or other extension.
Related formats
- STereoLithography
A simpler manufacturing mesh format without the same package and extension model.
- Wavefront OBJ
A text geometry format that commonly relies on external material and texture files.
- Binary glTF
A binary runtime-delivery container rather than a manufacturing package.
Sources & review
Fact review: 2026-09-19. Unknown fields are not inferred from the file extension.