.3mf3MF.gltfglTFlossless

Convert 3MF to glTF

Convert 3MF to glTF in your browser. The conversion runs on this page and the file never leaves your computer.

Drop your .3mf file

up to 250 MB · .3mf

Free, and it opens in this tab. Nothing is uploaded, and there's no account to make.

Runs locally · nothing uploaded

Before you convert: what this keeps and what it destroys

Preserved

  • The geometry, triangle for triangle
  • Overall dimensions and proportions
  • Watertightness, where the input is watertight
  • Colour
  • Separate parts and their positions

Destroyed

  • A recorded unit: glTF stores none

↺ the reverse: glTF → 3MF · about .3mf · about .gltf · just view it instead

Why people convert 3MF to glTF

The readable route from a print file to the web. Take GLB if you simply want it to work; take this when you want to look at what came across.

The JSON shows each object, its name and its material, which is a quick way to confirm that a multi-part model survived as multiple parts rather than being merged somewhere along the way.

The file is self-contained, with its buffer embedded as base64, at about a third more size than the binary form. 3MF's declared unit is converted into glTF's metres.

What you get

You get a plain-text glTF file you can open in an editor containing the same triangles the 3MF file described. No geometry is added, removed or approximated: mesh-to-mesh conversion is a change of container, and this site's tests check that the triangle count comes out identical.

The output uses metres, as required by the glTF specification.

Carried across: supported base or vertex colour, the supported part structure.

The conversion runs in your browser. Your file stays on your computer and is not uploaded.

What to check afterwards

  • 3MF declares its unit in the file. Check the output dimensions in the receiving application, especially when its import settings can override the unit.
  • The numbers change. glTF is read in metres and 3MF in millimetres, so every coordinate is rescaled. The result is the same physical size, but the numbers in the file are different numbers.

If you need something this conversion cannot give you

This pair loses very little. glTF carries what 3MF carries, so the main reason to choose a different target is what the receiving software accepts.

Going the other way

Convert glTF back to 3MF. The reverse conversion also works with mesh geometry. It does not reconstruct exact CAD surfaces. Material data and part structure lost in either direction cannot be restored by converting back. Keep the original file for later edits.

How we know this conversion works

This pair was checked against 13 files from the test corpus on 2026-09-04. Each run parses its own output back in and compares the bounding box, the triangle count and, for closed solids, the volume against the input.

A pair that fails those checks doesn't get a page. That's why this site lists 120 conversions and not the several hundred a format-times-format grid would suggest.