Convert glTF to 3MF
Free glTF to 3MF converter that runs in your browser. See real dimensions before you download, and get a watertight, slicer-ready file.
How to convert glTF to 3MF
- Drop your glTF file (with its textures, if separate) onto the converter — it opens in your browser, nothing is uploaded.
- Check the preview and the dimensions in mm; fix units or the up axis in “Units & orientation” if the size or orientation looks wrong.
- Choose 3MF as the output and click Convert. Several files download as one ZIP.
What carries over from glTF to 3MF
| glTF | 3MF | Result | |
|---|---|---|---|
| Colour / materials | Yes | Yes | Kept |
| Textures | Yes | No | Dropped |
| Units stored in file | Yes | Yes | Written as mm |
| Separate parts | Yes | Yes | Kept |
| Usual up axis | Y | Z | Rotated (switchable) |
About glTF files
glTF was developed by the Khronos Group, the body behind OpenGL and Vulkan, and version 2.0 was released in 2017 and later adopted as ISO/IEC 12113. The design goal was a lean transmission format that engines can load without heavy processing. In its text form, a .gltf file is JSON that lists scenes, nodes, meshes, materials, animations and accessors, and it points to external .bin buffers and image files, though buffers can also be embedded as base64 data. The same content packed into one file is called GLB. Because the JSON is readable, glTF is popular for tooling, pipelines and debugging, and for projects that want to diff or hand-edit assets. It uses metres, a right-handed coordinate system and +Y up, and its physically based materials are supported by most web and game engines.
About 3MF files
3MF was designed by the 3MF Consortium, whose members include Microsoft, Autodesk, HP, Stratasys and Prusa, as a modern replacement for STL in additive manufacturing. A .3mf file is a ZIP archive following the Open Packaging Conventions. Inside it, an XML model part holds the mesh, while other parts can hold thumbnails, textures and metadata. Unlike STL, the mesh shares vertices between triangles, which makes files smaller and keeps the surface connected. The core specification defines units, build items with placement transforms, and several objects in one file. Extensions cover materials, slices and beam lattices. Bambu Studio, OrcaSlicer and PrusaSlicer save their projects as 3MF with their own settings stored in extra files, so a project from one slicer may open in another with the geometry intact but the print profile ignored.
3D printing notes
For multi-colour and multi-part prints, 3MF is the format to use. Bambu Studio and OrcaSlicer open each part as a separate object, which lets you assign a different filament or setting to each one, and Prusa-family slicers do the same. Because the unit is stored in the file, a model does not arrive at the wrong size. Be careful with project files: a 3MF saved by Bambu Studio carries printer, plate and process settings that PrusaSlicer will not apply, and some slicers pick a different default when a model has no declared plate. MeshShift writes 3MF with several parts and keeps colours as base materials, and it reads 3MF for viewing, measuring and print checks.
Frequently asked questions
Is this glTF to 3MF converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your glTF file is never uploaded to a server. There is no sign-up, no watermark and no daily limit; very large files are limited only by your device's memory.
Should I use glTF or GLB?
Choose GLB when you want to share, upload or ship one file with textures inside. Choose glTF when you need to read or edit the JSON, keep textures separate, or let a version control system show changes. Both are the same standard and convert losslessly.
Is 3MF better than STL for 3D printing?
For most modern slicers, yes. 3MF records units, supports colours and several objects, and compresses well, while STL has none of those. STL remains the safer choice when a tool, a resin printer or a print service only advertises STL support.