Convert GLB to 3MF for 3D Printing
You get a 3MF package holding one merged mesh that any slicer opens. Expect to fix two things after import: the model arrives lying on its back, and it is 1,000 times too small because GLB counts in meters while the 3MF is written as millimeters.
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Why GLB models need converting before slicing
GLB is the single-file binary form of glTF, designed for web and AR delivery: metallic-roughness materials, embedded textures, node transforms, skins and animation in one download. Slicers have no interest in any of that. Bambu Studio, Orca Slicer, PrusaSlicer and Cura open STL, OBJ and 3MF (STEP only in some of them), so a model you pulled from Sketchfab, a photogrammetry app or a Blender glTF export has to be re-containerized before you can put it on a plate.
Here is the actual pipeline, which runs as server-side subprocesses: Blender 5.1.2 imports the GLB (Draco and meshopt compression are decoded first, and WebP textures are re-encoded so the importer accepts them), writes a temporary GLB, and then a trimesh program loads that with force='mesh' and exports the 3MF. The merge step matters: every mesh in the scene is collapsed into a single object with each node's transform applied, so a multi-part scene comes out assembled in the right relative positions instead of piled at the origin.
What you keep is the triangle mesh. What is dropped is everything else: materials, base-colour and normal textures, vertex colours, animation, skins, cameras, lights and the original object names. The 3MF specification can carry colour and print metadata, but our writer does not: it emits one object, one mesh, unit "millimeter", geometry only. No step converts units, so a 200 mm figure exported from Blender as 0.2 meters is written as 0.2 mm, and the Y-up GLB axes are written straight into a Z-up format, which lays the model on its back by 90 degrees about X.
That makes this page useful for one job: getting printable geometry out of a web-oriented asset. It is not a route for multi-material or painted prints, and it does nothing to make a mesh printable. Holes, non-manifold edges, flipped normals and self-intersections pass through untouched, because there is no repair step in the conversion path.
How to convert GLB to 3MF
- Check what your GLB depends on. Draco, meshopt and WebP files are handled, but a GLB that requires KTX2/Basis textures or Gaussian splatting is refused by the importer. Re-export without those extensions.
- Upload the .glb file. The guest limit is 50 MB per file, 100 MB with a free account, 200 MB on Plus and 1 GB on Pro.
- Download the result as yourname.3mf and open it in Bambu Studio, Orca, PrusaSlicer or Cura.
- Rotate the object +90 degrees about the X axis so it stands upright, then use "place on bed" or the drop-to-plate command.
- Scale the model to size. If the GLB was authored in meters, that is 100,000% (a factor of 1,000). Always check the resulting bounding box against the dimensions you expect before slicing.
- Run the slicer's mesh check and repair on the object, since nothing in the conversion fixes geometry errors.
What you get from this converter
- A plain 3MF package with one object and one mesh, unit millimeter, which slicers open without a plug-in or import dialog.
- Compressed GLB handled on the way in: Draco geometry and EXT_meshopt_compression are decoded, and WebP textures are converted before import so the file loads instead of erroring out.
- Node transforms are applied during the merge, so scenes with many parts keep their layout relative to each other.
- A GLB with nothing exportable (cameras and lights only, or no meshes) fails with a no-geometry error at the import step instead of producing an empty download.
- Nothing to install on either side: Blender and the mesh writer run on our servers, and you only need your slicer to open the output.
- Mid-size models in the tens of megabytes typically finish within a few seconds of upload; very dense scans take longer, and each engine step in this conversion is cut off at 600 seconds.
Video Tutorial
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Common questions about GLB to 3MF
Can I convert a GLB to 3MF with color?
Not here. Our 3MF output is geometry only, with no colour groups, textures or per-triangle materials, so a textured GLB arrives in the slicer as a single plain object. If you need a coloured result, paint or assign filaments to the object in Bambu Studio or Orca after import, or split the model into separate pieces in Blender, convert each piece on its own, and load them as separate objects you can assign different filaments to.
Why is the model only a few millimeters tall?
GLB measures in meters by specification; the 3MF writer labels the same numbers as millimeters and converts nothing. A 1.8 m character becomes 1.8 mm. Scale by 1,000 (100,000% in PrusaSlicer or Orca) and verify the dimensions readout.
Why does the model lie on its back in the slicer?
The GLB is Y-up and 3MF is Z-up, and the coordinates are written through without a rotation. Rotate +90 degrees about X in the slicer, or rotate the model in Blender before exporting the GLB if you convert the same asset often.
Is 3MF a better choice than STL for this?
From this converter both carry just the mesh, so the practical difference is that 3MF is a compressed XML package with a declared millimeter unit and generally a smaller file, while our STL output is raw binary triangles with no unit at all. Both need the same scale and rotation fix. Pick 3MF if your slicer's project workflow is built around it.
My GLB has several separate parts. Can I arrange them individually?
Not from one conversion: all meshes are merged into a single object, so the slicer treats them as one body. To keep parts independent, export each part as its own GLB from your 3D tool and convert them one at a time, then add them to the same plate.
Does the converter repair the mesh or make it watertight?
No. There is no hole filling, no manifold repair and no normal correction in this path beyond what the exporters do natively. Use your slicer's repair function, Microsoft's 3D Builder, Meshmixer or Netfabb if the mesh needs fixing.
Which GLB files fail on this page?
Files that require KTX2/Basis textures or the Gaussian splatting extension, since the importer refuses them; scenes that contain only cameras and lights, which produce no geometry; and truncated or corrupted downloads, which come back as unreadable. Re-export from the source tool and try again.
How long do you keep my files?
The conversion runs on our servers. Your uploaded GLB is deleted when the job finishes, and the 3MF download link lasts about four hours before the file is removed automatically. File names, sizes and conversion outcomes are logged, and if you are signed in the job appears in your conversion history.