You download a 3D model, open it, and half the textures are missing. Or the file is 180 MB and your browser gives up. Nine times out of ten the problem isn’t the model — it’s that the wrong one of the many 3D file formats got used for the job.
Each format was built for a different pipeline. OBJ came out of 1980s CAD work. FBX exists to move animation between Autodesk apps. glTF was designed for the web. Picking correctly takes about thirty seconds once you know what each one actually carries, and it saves the afternoon you’d otherwise spend re-linking textures.
The short answer
For anything that loads in a browser — product configurators, spinnable models on a store page, AR previews — use GLB. For a rigged character moving between Maya, Blender and Unreal, use FBX. For a static shape with no animation and no fussy materials, OBJ still works fine. For 3D printing, STL. For iPhone AR, USDZ.
Format comparison at a glance
| Format | Animation | PBR materials | Textures embedded | Typical use |
| GLB | Yes | Yes | Yes (single file) | Web, AR, product mockups |
| glTF (.gltf) | Yes | Yes | No (separate files) | Web pipelines, editing |
| OBJ | No | No | No (.mtl + images) | Static props, CAD exchange |
| FBX | Yes | Partial | Optional | Game engines, VFX, rigging |
| STL | No | No | No | 3D printing |
| USDZ | Yes | Yes | Yes | iOS AR Quick Look |
glTF and GLB: the same standard, two wrappers
glTF is a Khronos Group open standard, and people in the industry keep calling it “the JPEG of 3D.” That nickname is doing real work — it means an open, well-specified format that everything supports and nobody has to license.
Here’s the part that trips people up. glTF and GLB aren’t competitors. They’re two packagings of the identical data.
A “.gltf” file is JSON. It’s human-readable, and it usually points outward to a “.bin” file holding the mesh data plus a folder of PNG or JPG textures. Move the “.gltf” without its neighbours and you get a grey blob.
A “.glb” file is the binary version. Geometry, materials, textures, animation — all sealed into one file. Nothing to lose, nothing to re-link. That’s why almost every browser-based viewer and every mockup tool defaults to it.
Rule of thumb: edit in glTF, ship in GLB.
Both support physically based rendering, which means the material data actually describes how a surface behaves. Metallic, roughness, normal, emissive, occlusion — the renderer uses these to work out how light hits brushed aluminium versus matte cardboard. It’s the reason a glTF can of soda looks like metal and an OBJ version of the same can looks like painted plastic.
OBJ: old, simple, still useful
Wavefront OBJ dates back to the 1980s and its limits show. It stores vertices, faces and UV coordinates. That’s basically it.
Materials live in a separate “.mtl” file using an old Phong-style model — diffuse colour, specular highlight, a shininess value. No metalness. No roughness. No proper normal map slot. Feed an OBJ into a modern PBR renderer and you’ll spend twenty minutes rebuilding the material by hand.
It also can’t store animation. Not “poorly” — not at all. Each frame would need its own file.
So why does OBJ refuse to die? Because everything reads it. Every modeller, every slicer, every ancient piece of CAD software from 2004. When you need a static shape to survive a trip between two programs that agree on nothing else, OBJ is the safe handoff.
FBX: built for animation, heavy by nature
FBX is Autodesk’s proprietary format and it’s the standard currency of game and film pipelines. It carries skeletal rigs, skinning weights, blend shapes, animation takes, cameras, lights and scene hierarchy — the whole production scene, not just the object.
That completeness is also why FBX files balloon. A single product model that ships as a lean GLB can arrive as an FBX several times larger, because it’s dragging along scene metadata, multiple animation takes and often uncompressed embedded textures.
Two more practical headaches worth knowing before you commit:
- FBX comes in ASCII and binary variants, and some importers only accept one.
- Version mismatches between FBX 2016, 2019 and 2020 exports cause silent import failures more often than any other format.
Use FBX when animation rigs need to move between DCC applications. Don’t use it to put a product on a website.
STL and USDZ: the two specialists
STL is triangles and nothing else. No colour, no UVs, no materials. It exists so slicers can turn a mesh into printer toolpaths, and for that one job it’s perfect. Anyone who has tried to texture an STL knows the feeling.
USDZ is Apple’s zipped USD package for AR Quick Look on iOS. Tap a link on an iPhone, the sofa appears on your floor. If your audience is on iPhones and you want AR without an app, you need a USDZ alongside your GLB. Most modern exporters can produce both from the same source.
Which format should you actually pick?
Work backwards from where the model ends up.
Product visuals and mockups. GLB. A browser can load it, a viewer can spin it, and the PBR materials keep fabric looking like fabric. If you’re weighing up software for this, the roundup of best 3D mockup tools covers which ones actually export clean GLB rather than a flattened render.
Websites and product configurators. GLB with Draco or Meshopt compression applied. Draco compresses mesh geometry aggressively and is widely supported by web viewers. Compress your textures separately — an uncompressed 4K texture set will dwarf the geometry every time.
Game engines. FBX going in, engine-native formats after that. Unity and Unreal both handle glTF now, but rigging workflows are still smoother through FBX.
Apparel and softgoods. Depends on the tool. Most 3D clothing design software exports to glTF or FBX, and simulation data usually doesn’t survive either — you’re exporting a baked result, not a live garment.
Print production. STL for the printer, plus a PDF or vector for anything flat. Vector work belongs in Illustrator, and there’s a separate walkthrough on building a 3D mockup in Illustrator if that’s your pipeline.
Three mistakes that cause most import problems
Sending a .gltf without its folder. The JSON is a manifest, not a container. Zip the whole directory or export GLB instead.
Assuming materials transfer. They rarely do cleanly. Converting FBX to glTF usually needs a material rebuild, because the two describe surfaces differently. Budget time for it.
Ignoring scale and axis. Blender is Z-up. Maya and glTF are Y-up. Models arriving on their side or 100× too big are almost always an axis or unit mismatch, not a broken file.
What is the difference between GLB and glTF?
They hold identical data in different wrappers. glTF is readable JSON that references external “.bin” and texture files; GLB is one binary file with everything embedded. GLB is better for sharing and web delivery, glTF is better mid-pipeline when you want to edit textures separately.
Which 3D file format is best for the web?
GLB, comfortably. It loads natively in browser viewers, holds PBR materials, supports animation, and travels as a single file. Add Draco compression for large meshes.
Can OBJ files store animation?
No. OBJ stores static geometry and UVs only. Any animation has to come from a format like glTF, FBX or USD.
Why is my FBX file so large?
Usually embedded uncompressed textures, plus scene data — multiple animation takes, cameras, lights, hierarchy. Exporting the same mesh to GLB with compressed textures typically cuts the size dramatically.
Do I need to understand 3D formats to make product mockups?
Not really. Browser-based generators handle the format entirely for you — you upload a flat PNG and download an image or video. Formats matter once you start importing custom models or embedding a viewer. If you’re new to the whole idea, start with what is a 3D mockup and come back to this when you need custom geometry.
Conclusion
Most 3D file format confusion disappears once you stop asking “which is best” and start asking “where is this going.” GLB for the web and for mockups. FBX for animation pipelines. OBJ for a static handoff. STL for printing. USDZ for iPhone AR.
Get the destination right and the format picks itself. Want to skip the file wrangling entirely? Browse the ready-made 3D models on 3dmockup.co, drop your artwork on, and export a finished visual — no exporter settings required.