Format Odyssey

FILE FORMAT GUIDE

3MF File (.3MF): What It Is & How to Open It

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 for the reviewed ZIP container signature. This confirms the container, not the inner 3D Manufacturing Format structure.

Check supported file headers

Quick facts

Extension
.3mf
Format
3D Manufacturing Format
Category
3d
MIME type
model/3mf
Standard / developer
3MF Consortium / ISO/IEC JTC 1
Open with
PrusaSlicer

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.

How to open 3MF

PrusaSlicerWindows / macOS / Linux

Open or drag the .3mf file into PrusaSlicer to inspect the included model and project settings before preparing a print.

3MF files — Prusa Knowledge Base

Common uses and compatibility

  • Transfer 3D models and manufacturing information between design, service and printing systems

Things to check

  • Support for Core does not imply support for every materials, production, secure-content or other extension.

Advanced inspection

These developer and command-line workflows inspect structure or metadata. They are not the default way most people open the file.

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

3MF Core Specification 1.3.0

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

Sources reviewed 2026-09-19.