cadformats.com

Your file never leaves your browser.

cadformats.com/convert/gltf-to-3mf

.gltfglTF→.3mf3MFlossless

Convert glTF to 3MF

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

Drop your .gltf file

up to 250 MB · .gltf

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
  • The unit, recorded in the file
  • Colour
  • Separate parts and their positions

Destroyed

  • Animation, rigs, cameras and lights, if the file has them

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

Why people convert glTF to 3MF

The better way to print a glTF asset, and the one to choose whenever your slicer accepts 3MF.

Compared with going to STL you keep three things. The unit ends up recorded in the file instead of assumed. Colour survives, which matters because glTF assets almost always have some. And separate nodes stay separate objects on the plate rather than merging into a single body.

Coordinates are multiplied by 1000 on the way from metres to millimetres. The one thing to confirm before uploading is that your .gltf carries its own geometry: an export that left the vertex data in a neighbouring .bin has nothing in the file you hand over, and the page will tell you which file it went looking for.

What you get

You get a binary 3MF file containing the same triangles the glTF 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.

Carried across: the unit, recorded in the file, 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

  • glTF and GLB use metres by specification. This converter interprets the source coordinates that way. If the model was authored at a different scale, confirm a known dimension before using the output.
  • The numbers change. 3MF is read in millimetres and glTF in metres, 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. 3MF carries what glTF carries, so the main reason to choose a different target is what the receiving software accepts.

Going the other way

Convert 3MF back to glTF. 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 1 file 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.