How do I shrink a big GLB?

Two levers, both big: compress the mesh with Draco or Meshopt, and compress textures to KTX2/Basis. Run it through gltf-transform (gltf-transform optimize in.glb out.glb) or gltfpack — a 40 MB GLB routinely drops to 2–4 MB with no visible loss. Oversized baked-in textures are almost always the real weight, not the mesh.

GLB or glTF — which should I ship?

Same format, two packagings. GLB is a single binary — ship this to the web, AR and engines. Plain .gltf is JSON plus separate .bin and texture files, useful when you want to read or edit the JSON by hand. For delivery, always GLB.

Does the animation play in this viewer?

Yes — if the GLB carries animation, the viewer plays the first clip automatically (you'll see an ▶ Animation tag on the model). It's a fast way to confirm the animation survived export. To scrub between multiple clips or control playback frame by frame, wire it into or a Three.js scene.

Will this GLB work in or Three.js?

If it loads and looks right here, it's valid glTF and will load in , Three.js, Babylon and most engines — they share the same loader core. What differs between them is performance, and that comes down to the file size and triangle count shown below.

Can I use a GLB for AR on an iPhone?

iOS AR Quick Look wants USDZ, not GLB; Android's Scene Viewer takes GLB. The tag bridges both if you supply a GLB plus a USDZ. Check the model here first, then export the second format.

Is my GLB uploaded anywhere?

No — it's read and rendered on your own device. Nothing is sent to a server, so unreleased product models and client work stay private.

GLB viewer

Open a .glb and see exactly what you'll be shipping — the model, its materials, and how heavy the file is — before you wire it into a Three.js scene, a <model-viewer> tag or an AR view.

Sample model — drop your own GLB

Drag to rotateScroll to zoom

The .glb is read and rendered in your browser with its own materials — nothing is uploaded. The file size and triangle count below are the two numbers that decide whether it's web-ready.

GLB bundles everything — including the weight

GLB is the binary side of glTF: one file that packs the mesh, the PBR materials, every texture and any animation into a single blob a browser, AR viewer or game engine reads natively. That self-containedness is why it's the default for the web and AR — hand someone a GLB and there are no missing-texture surprises.

It's also why a GLB can balloon. The textures are usually the heavy part: a couple of 4K images baked in will turn a small mesh into a 40 MB download. The file-size readout above is the number to watch — if it's large and the geometry is simple, it's the textures, and that's fixable before you ship.

What I check before shipping one

1. File size vs your budget: For the web, aim low — a hero model over ~5–10 MB is a slow load on mobile data. If the size below is alarming, compress before you ship.
2. Do the materials render: This viewer lights the model with studio image-based lighting, so PBR materials show roughly as a real engine will draw them. Flat, chalky or missing means the export dropped them.
3. Triangles for real-time: Smooth frame rates on mid-range phones like budgets in the tens-to-low-hundreds of thousands of triangles per model, not millions. The count below says whether you need to decimate.
4. Orientation & scale: glTF is Y-up and metres by convention. If it lands sideways or giant in your engine, it was exported against that convention — fix it at export, not in code.

GLB, glTF and USDZ

Format	Packaging	Animation	Best for
GLB	Single binary	Yes	Web, Android AR, game engines
glTF	JSON + .bin + textures	Yes	Inspecting or editing by hand
USDZ	Single (Apple)	Yes	iOS AR Quick Look

GLB is the web and cross-engine default; USDZ is the iOS AR sibling you export alongside it. Same model, packaged for where it's going.

How to view a GLB file

1Click “Open GLB file,” or drag your .glb onto the viewer — it loads locally, with no upload.
2Drag to orbit and scroll to zoom; the model shows with its real materials under studio lighting.
3Read the file size and triangle count below — the two numbers that decide whether it's web-ready.

GLB viewer — FAQ

How do I shrink a big GLB?: Two levers, both big: compress the mesh with Draco or Meshopt, and compress textures to KTX2/Basis. Run it through gltf-transform (gltf-transform optimize in.glb out.glb) or gltfpack — a 40 MB GLB routinely drops to 2–4 MB with no visible loss. Oversized baked-in textures are almost always the real weight, not the mesh.
GLB or glTF — which should I ship?: Same format, two packagings. GLB is a single binary — ship this to the web, AR and engines. Plain .gltf is JSON plus separate .bin and texture files, useful when you want to read or edit the JSON by hand. For delivery, always GLB.
Does the animation play in this viewer?: Yes — if the GLB carries animation, the viewer plays the first clip automatically (you'll see an ▶ Animation tag on the model). It's a fast way to confirm the animation survived export. To scrub between multiple clips or control playback frame by frame, wire it into <model-viewer> or a Three.js scene.
Will this GLB work in <model-viewer> or Three.js?: If it loads and looks right here, it's valid glTF and will load in <model-viewer>, Three.js, Babylon and most engines — they share the same loader core. What differs between them is performance, and that comes down to the file size and triangle count shown below.
Can I use a GLB for AR on an iPhone?: iOS AR Quick Look wants USDZ, not GLB; Android's Scene Viewer takes GLB. The <model-viewer> tag bridges both if you supply a GLB plus a USDZ. Check the model here first, then export the second format.
Is my GLB uploaded anywhere?: No — it's read and rendered on your own device. Nothing is sent to a server, so unreleased product models and client work stay private.

Do more with your GLB

Convert it for printing or editing, unpack it to text, or open a different format.

GLB → STL GLB → OBJ GLB → glTF FBX → GLB glTF viewer FBX viewer All 3D viewers All 3D converters

Need the model, not just a viewer?

Describe it or drop in a photo — Sculptor generates a fresh 3D model and exports it as a web-ready GLB, plus STL and OBJ, ready to open right back here.

Generate a 3D model