Convert OBJ to glTF
Free OBJ to glTF converter that runs in your browser. See real dimensions before you download.
How to convert OBJ to glTF
- Drop your OBJ 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 glTF as the output and click Convert. Several files download as one ZIP.
What carries over from OBJ to glTF
| OBJ | glTF | Result | |
|---|---|---|---|
| Colour / materials | Yes | Yes | Kept |
| Textures | Yes | Yes | Kept |
| Units stored in file | No | Yes | Written as mm → metres |
| Separate parts | Yes | Yes | Kept |
| Usual up axis | Y | Y | Unchanged |
About OBJ files
OBJ comes from Wavefront Technologies' Advanced Visualizer software in the 1980s, and it has outlived the product. A file is plain text: lines starting with v define vertices, vt texture coordinates, vn normals, and f faces that reference those lists by index. Faces may be triangles, quads or larger polygons, and the g and o keywords group faces into named objects. Appearance is not in the OBJ at all; a line called mtllib points to a separate .mtl file that lists materials with diffuse colours and texture image names. The format is verbose, has no official unit and no scene hierarchy or animation, but it is trivial to read and write. That is why scanners, photogrammetry tools, sculpting programs and game pipelines still use it to move static meshes around.
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.
3D printing notes
Slicers import OBJ geometry and ignore the material file, so what you print is the shape only. Bambu Studio and OrcaSlicer can use the colours from an OBJ for multi-colour assignment on import, but results depend on the exporter. The main trap is orientation and scale. Blender usually writes Y-up files while slicers expect Z-up, so a model may arrive lying on its back, and a model sculpted at one unit per metre can be tiny. MeshShift has an Up-axis fix that rotates Y-up models so they stand upright, shows real dimensions before conversion, and can convert OBJ to STL or 3MF in the browser.
Frequently asked questions
Is this OBJ to glTF converter free and private?
Yes. The conversion runs in your browser with JavaScript and WebAssembly, so your OBJ 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.
Why does my OBJ import without its colours or textures?
The colour information is in a separate .mtl file and image files. If the MTL or textures are missing, renamed or in another folder, the importer shows plain grey geometry. Keep the OBJ, MTL and images together, or convert to GLB, which packs them in one file.
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.