OBJ Converter
FileFlip converts OBJ files into 13 other formats entirely inside your browser, using Assimp compiled to WebAssembly. The OBJ file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an OBJ file?#
- Drop your OBJ file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
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 happens to a OBJ file#
FileFlip converts OBJ into 13 formats with Assimp, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | 3D Models |
|---|---|
| File extension | .obj |
| FileFlip support | Read and written |
| Conversions available | 13 |
| Engines | Assimp |
| Downloaded to your browser | 11.2 MB on the first conversion, then cached |
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.
The OBJ file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
OBJ 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.