OBJ to glTF Converter
FileFlip converts OBJ to glTF entirely inside your browser, using Assimp compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an OBJ file to glTF?#
- Drop your OBJ file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to glTF and the conversion starts on its own. FileFlip downloads 11.2 MB of WebAssembly the first time and nothing after that, then runs Assimp on your own machine.
- Save the glTF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting OBJ to glTF lose quality?#
Not in the sense of pixels or samples. Converting OBJ to glTF rebuilds the file in glTF's own model rather than re-encoding it, so everything glTF can represent comes through exactly and anything it cannot has to be dropped. Expect the geometry to be exact, and anything the target has no place for, such as a rig, to be left behind.
Is it safe to convert OBJ files online?#
Yes, because nothing is uploaded. FileFlip converts OBJ files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What OBJ to glTF actually does to the file#
Converting OBJ to glTF runs on Assimp, downloads 11.2 MB of WebAssembly the first time and nothing after that, rebuilds the file in the target's own model.
| Engine | Assimp |
|---|---|
| Conversion path | One step: OBJ → glTF |
| Downloaded to your browser | 11.2 MB, once, then cached by your browser |
| Quality | Rebuilt in the target's model |
| You get back | One file, or a ZIP when the source carries separate materials or buffers |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Materials | Sometimes | Survives for some files and not others. |
| Textures | Sometimes | Survives for some files and not others. |
| Skeleton and animation | Sometimes | Survives for some files and not others. |
Worth knowing before you start:
- the result is a single file when the model has no external materials or buffers, and a ZIP when it does
What is an OBJ file?#
An OBJ file is a plain-text 3D geometry format that Wavefront Technologies designed for its Advanced Visualizer software, storing vertex positions, texture coordinates and normals as human-readable lines of ASCII text.
Use OBJ when a static mesh needs to move between two different applications with the least risk of anything being misread.
Convert away from OBJ when the model needs animation, a skeleton, or to travel as a single file without a companion MTL.
What is a glTF file?#
A glTF file is a JSON scene description, developed by the Khronos Group and first released in 2015, that lists a model's meshes, PBR materials, animations and scene hierarchy while its binary geometry and textures sit alongside it in separate buffer and image files.
Use glTF's JSON form when a pipeline needs to inspect or hand-edit the scene structure directly, since it's plain, indexed JSON.
Convert glTF to GLB when the model needs to travel or load as a single file instead of a folder of JSON, buffers and textures.
OBJ to glTF questions people ask#
Can OBJ files have animation?
No, OBJ has no concept of a skeleton, bone weights or keyframes, so it cannot store animation of any kind. It only describes a static mesh at one point in time; formats like FBX or glTF are needed for anything that moves.
What is an OBJ file used for?
An OBJ file stores the geometry of a single 3D model: its vertices, faces, texture coordinates and normals, written as plain text. It's used to move a static mesh between applications, since almost every 3D tool on every platform can read it.
Why does converting an OBJ file produce a ZIP?
An OBJ file only holds geometry; its material definitions, including which texture image goes where, live in a separate companion MTL file that the OBJ references by name. A converter has to hand back both files together, which is why an OBJ export comes as a ZIP rather than a single file.
Does OBJ support color and materials?
OBJ itself stores no colour or material data at all; that information lives in the companion MTL file it references, which defines diffuse and specular colours, transparency and texture maps using the Phong reflection model. Without the matching MTL file, an OBJ opens as a plain grey mesh.