OBJ to GLB Converter
FileFlip converts OBJ to GLB 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 GLB?#
- 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 GLB 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 GLB file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting OBJ to GLB lose quality?#
Not in the sense of pixels or samples. Converting OBJ to GLB rebuilds the file in GLB's own model rather than re-encoding it, so everything GLB 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 GLB actually does to the file#
Converting OBJ to GLB 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 → GLB |
| 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 |
| 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. |
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 GLB file?#
A GLB file is glTF's binary packaging, developed by the Khronos Group, wrapping the JSON scene description together with its geometry buffers and textures into one self-contained file instead of a JSON document with separate buffer and image files beside it.
Use GLB whenever a model has to be handed to a web viewer, AR app or game engine as a single upload.
Convert GLB back to glTF's JSON form only when something inside the file needs to be read or edited directly.
OBJ to GLB questions people ask#
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.
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.
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.