Free online GLB to 3MF converter

A slicer or printer-management application may require 3MF instead of a web-oriented GLB model. Converting the file lets you move a model from a website, AR viewer, or real-time application into a print-preparation workflow.

What the GLB format is

GLB is the binary form of glTF, a format designed for efficient delivery in websites, game engines, AR applications, and real-time viewers. A single GLB file can contain mesh geometry, textures, physically based materials, animations, cameras, and lights.

Blender, 3ds Max, Maya, Unity, Unreal Engine, scanning and photogrammetry applications, web configurators, and online 3D viewers commonly use GLB. The format is optimized for displaying an asset, not for defining a printable, watertight solid or a complete manufacturing job.

What the 3MF format is

3MF is a ZIP-based manufacturing container whose resources describe one or more meshes. It can include units, colors, material assignments, thumbnails, build-plate placement, and, through supported extensions, slicer or print-job data.

Compared with STL, 3MF can keep units and multiple objects in one structured package instead of relying on ambiguous unit conventions and separate files for related information. PrusaSlicer, OrcaSlicer, Bambu Studio, UltiMaker Cura, Microsoft 3D Builder, and other applications can open 3MF, but their handling of materials, colors, assemblies, and embedded print settings is not identical.

Convert with 101convert

1. Open the GLB-to-3MF converter on 101convert.com. The conversion can be performed for free without installing software.
2. Select the source file, such as model.glb, and choose 3MF as the output format.
3. Start the conversion and download the resulting model.3mf file when processing finishes.
4. Open the output in the target slicer. Check its dimensions, orientation, object count, colors or material assignments, and layer preview before printing.

An automatic conversion transfers only information supported by the converter and 3MF output. It does not guarantee that a GLB has printable geometry or that every texture and material will survive.

Convert locally with Blender

1. Install Blender and, if required by your version, a compatible 3MF import/export extension. 3MF support is not available in every Blender installation by default.
2. Import the file through File → Import → glTF 2.0 (.glb/.gltf).
3. Remove cameras and lights if the file is intended only for printing. Keep the meshes that need to be exported, then use Object → Apply → Rotation & Scale after confirming their intended dimensions.
4. Inspect the model in solid and wireframe views. Blender's 3D Print Toolbox can help identify non-manifold edges, holes, intersecting surfaces, and other common problems; repair them before export.
5. Confirm the scene units and measure a known feature. glTF defines one scene unit as one meter, but the asset creator may have modeled an object at an unintended real-world scale, and import or export software may interpret units differently.
6. Use the installed extension through File → Export → 3MF, then save the file as model.3mf.
7. Open the exported file in the slicer and inspect the generated toolpaths and layer preview.

Use 3D Builder on Windows

1. Open the GLB file in Microsoft 3D Builder, if the installed version supports GLB import.
2. Check the model's dimensions, orientation, separate parts, and repair warnings.
3. Choose File → Save as and select 3MF.
4. Open the saved file in the target slicer and verify the scale and toolpaths.

Quality and compatibility limits

Conversion changes a real-time scene into a print-oriented model. Animations, cameras, lights, skinning, and most scene behavior are normally discarded. Textures and PBR materials may be omitted, flattened, or simplified because slicers commonly use per-face color, filament assignments, or their own material systems rather than GLB's texture workflow.

Verify scale. A GLB's glTF units are meters, while slicers commonly display millimeters. A unit conversion error can make the result 1,000 times too large or too small. Measure a known feature after import and correct the dimensions before exporting or slicing.

A GLB may contain multiple meshes. The converter or slicer may preserve them as separate parts, merge them, or reject overlapping and disconnected components. Keep separate meshes only when the target workflow supports multipart models and independent materials or print settings are needed.

For reliable printing, the final mesh should be closed, have consistently oriented normals, contain no zero-area faces or self-intersections, and have enough polygon resolution for the intended detail. A model that looks correct in a 3D viewer can still produce missing surfaces, non-manifold regions, or invalid toolpaths. Always validate the exported 3MF in the target slicer before sending it to a printer.