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3MF File Format (.3mf)

A 3MF file is a ZIP archive of XML documents, published by the 3MF Consortium in 2015 as 3D printing's replacement for STL, adding the colour, material, unit and multi-object placement data STL never had.

.3mf3D Models

3MF at a glance#

Full name3D Manufacturing Format
File extension.3mf
Category3D Models
Developer3MF Consortium
First released2015
MIME typesmodel/3mf
CompressionLossless
Specification3MF Core Specification
FileFlip supportFileFlip reads and writes this format

What a .3mf file can hold#

These are the things a 3MF file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Embedded metadataYes
Textures and materialsYes

Strengths and limitations of 3MF#

What 3MF does well

  • Carries colour, material, units and multiple objects with their build-plate placement, none of which STL can hold
  • A ZIP of XML, so any archive tool can look inside without special software
  • Backed by a consortium of major CAD and printer vendors rather than one company, and an ISO standard since 2025

Where 3MF falls short

  • Slicer and printer support still trails STL, since STL had a decades-long head start
  • The base spec covers geometry, colour and materials; some printer-specific features rely on vendor extensions
  • Being XML inside a ZIP, a 3MF is more work to hand-edit than a plain-text format

Use 3MF over STL whenever colour, material or multiple positioned objects need to travel with the geometry to the printer.

Convert 3MF to STL only when the destination software is old enough to not support 3MF at all.

How to open a .3mf file#

A .3mf file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts 3MF into a format your machine already opens, and it does it in the browser tab rather than on a server.

PlatformPrograms that open it
WindowsPrusaSlicer, Cura, 3D Builder, Bambu Studio
macOSPrusaSlicer, Bambu Studio
LinuxPrusaSlicer, Cura
WebFileFlip

3MF questions people ask#

What is a 3MF file?

A 3MF file is a 3D printing format, a ZIP archive of XML, published by the 3MF Consortium in 2015 to replace STL. It adds colour, material, real-world units and multiple objects with their placement on the build plate, none of which STL can store.

Is 3MF better than STL?

3MF can carry colour, material, units and multiple positioned objects in one file, all of which STL simply has no fields for. STL still has broader support since it's decades older, so the better choice depends on whether the printer and slicer being used actually support 3MF.

Can I open a 3MF file with a ZIP tool?

Yes, a 3MF file is literally a ZIP archive containing XML documents, so any standard archive utility can open it and show the files inside. That doesn't render the model, but it does let you inspect the raw geometry and metadata directly.

Does my 3D printer support 3MF?

Most current slicers, including PrusaSlicer, Cura and Bambu Studio, read 3MF natively and it's become the default project format for several of them. Older or budget slicer software may still expect STL, so it's worth checking a specific printer's software before relying on 3MF alone.

Converting 3MF files#

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.