FBX vs glTF vs OBJ: Which 3D Model Format Should You Actually Use?

Your model looks perfect in Blender and lands in the engine wrong

You export a character, drag it into Unity, and the rig is gone. Or the materials come in gray. Or the whole thing is rotated face-down and scaled to the size of a building. Nine times out of ten the culprit is not your modeling. It is the file format you exported and what that format can and cannot carry.

There are three formats you will actually run into as a game dev: OBJ, FBX, and glTF (usually shipped as the binary GLB). They are not interchangeable. Each was built for a different job, and picking the wrong one quietly throws away data you needed. Here is the honest breakdown of what each one keeps, what it drops, and when to reach for it.

The Utah teapot, the go-to test model for 3D pipelines. Image: Wikimedia Commons

OBJ: the plain text workhorse

OBJ is the oldest of the three, born at Wavefront Technologies decades ago. It is a human readable text format that stores vertices, faces, UVs, and normals. That is basically it. Materials live in a separate .mtl file that rides alongside the .obj, which is why people forget to copy it and end up with an untextured blob.

The big limitation: OBJ has no concept of bones, skeletons, or animation. It cannot carry a rig. It is a snapshot of static geometry and nothing more. Because everything is stored as text, the files are also large and slow to parse next to binary formats.

So when is OBJ the right call? Static props with no animation. Rocks, crates, weapons, furniture, hard surface kitbash pieces. It is also the standard for 3D printing and quick geometry handoffs between programs that both speak it, which is nearly all of them. If your asset never needs to move on its own, OBJ is simple and reliable.

FBX: the game pipeline default

FBX is the format most studios actually ship on. It is an Autodesk format, and it carries almost everything: meshes, full skeletal rigs, skeletal animation, blend shapes (morph targets), object hierarchies, cameras, lights, and embedded material references. Both Unity and Unreal import it natively with zero extra packages, which is the main reason it became the de facto standard.

If you are buying or selling a rigged, animated character, FBX is what it should come as. Most game-ready packs on DevLoot ship as FBX for exactly this reason: it is the one format you can hand to a Unity or Unreal user and trust that the rig and animations survive the trip.

FBX carries the rig, the animation, and the hierarchy. That is why it won the game pipeline, even though it is closed and aging.

The catch is that FBX is proprietary and closed. Autodesk controls the spec, and it has not seen serious new development in years. Plenty of devs treat it as a long term dead end. It is not going anywhere soon, since the entire industry runs on it, but it is not the future either. There are also two flavors, binary and ASCII, and some tools only read one, which causes the occasional import headache.

glTF and GLB: the open, modern option

glTF is the new kid that grew up fast. It is an open standard from the Khronos Group, the same people behind OpenGL and Vulkan, and it gets called "the JPEG of 3D" for a reason. The current version is glTF 2.0. It supports physically based rendering materials out of the box, skeletal animation, and morph targets, so feature-wise it overlaps a lot with FBX. The binary packaging, GLB, bundles meshes, textures, and animation into a single tidy file.

Where glTF pulls ahead is size and speed. It stores geometry in a layout that maps closely to how the GPU wants it, so it is roughly five times smaller and around ten times faster to read than a bulky text format like OBJ. That makes it the default for anything on the web, in AR, or on mobile, where every kilobyte and millisecond counts. three.js, Babylon.js, and most WebGL frameworks treat GLB as their native tongue.

On the engine side, Unreal imports glTF and GLB directly. Unity does not switch it on by default the way it does FBX, but the Unity glTFast package (com.unity.cloud.gltfast, now maintained by Unity) handles both import and export at edit time and at runtime, across all the render pipelines. If your game streams or downloads models while it is running, glTF is the format you want, because it loads fast and is genuinely open.

What about USD?

You will hear more about USD (Universal Scene Description), Pixar's format that studios are adopting to move whole scenes between tools. It is powerful, but it is a heavyweight scene interchange format, not a lightweight per-asset delivery format. For shipping a single model into a game, OBJ, FBX, and glTF are still the practical choices.

The quick decision guide

Strip away the history and it comes down to a few questions.

• Static prop, no animation, maximum compatibility? OBJ is fine. Just remember the .mtl file.
• Rigged or animated asset headed for Unity or Unreal? FBX. It is the safe default and the rig survives.
• Web, AR, mobile, or anything loaded at runtime? glTF or GLB, every time.
• Buying an asset? Check that it ships in the format your engine wants, and that a rigged character actually includes the rig and not just the mesh.

One last thing that bites everyone regardless of format: scale and orientation. Different tools disagree on units and which axis points up, which is why a model shows up giant and face-down. That is a separate fight from the format itself, and we covered the fixes in our guide on exporting from Blender to Unity without breaking scale and rotation. If your textures look flat or wrong after import, that is usually a material or map issue, not the format, and our piece on how normal maps work in Unity walks through the most common one.

Pick the format for the job, not out of habit. Most of the "my model is broken" panics trace back to using a format that was never built to carry the thing you lost.