Drop a .glb file to spin it, play its animations, and see exactly what it is made of. The file stays in this tab.
What This Tool Does
Drop a .glb and two things happen at once. You get a 3D view you can spin,
zoom and pan, with its animations playing. And you get the numbers: how many
triangles, how many draw calls, which materials, how large each texture really
is, and which glTF extensions the file depends on.
Most free viewers do the first half. The second half is usually a command-line
tool. Both matter, because "does it look right" and "is it fit to ship" are
different questions and you normally need to answer them together.
How to Use It
Drop a file on the box, click to pick one, or press Try a sample model if
you have nothing to hand.
Drag inside the view to orbit, scroll to zoom, and drag with the right button
to pan. Reset view puts the camera back where it started.
Wireframe and No textures strip the model down when you are looking at
topology or shading rather than the finished look. Grid and Bounding box
give you a sense of scale — useful when a model turns out to be a hundred times
larger than you expected.
Reading the Numbers
Triangles and draw calls are the two figures that predict performance, and
they measure different things. Triangles are how much the GPU has to shade;
draw calls are how many times the CPU has to interrupt it. A model with 5,000
triangles spread over 200 draw calls is often slower than one with 50,000
triangles in a single call.
Texture weight is the number that usually explains a surprising file size.
The panel reports what each image actually occupies inside the GLB, not the
decoded pixel dimensions — so you can see straight away when a 12 MB file is 11
MB of textures.
Extensions tell you what the file assumes its viewer can do. Anything
listed as required is not optional: a viewer without it will not open the file
at all.
Everything Stays on Your Machine
Your file is read and parsed in this browser tab. It is never uploaded, queued
or stored. Once the page has loaded, you can disconnect from the network and
open any file that needs no Draco or KTX2 decoding — the only requests this
tool ever makes are for a compression decoder, when your file actually needs
one, and for the sample model, only if you press Try a sample model.
Frequently asked questions
- Is my model uploaded anywhere?
- No. Your file is read with the browser's own file API and parsed in this tab — it is never sent anywhere. The only two things this tool ever fetches from the server are a compression decoder, needed only if your file uses Draco or KTX2 compression, and the sample model, fetched only if you press Try a sample model. Open a file that needs neither of those and you can disconnect from the network the moment the page has loaded.
- Why does it only accept .glb and not .gltf?
- GLB packs the geometry, the textures and the animation into one binary file, so dropping one file is enough. A .gltf is JSON that points at a separate .bin and a folder of image files, so opening one properly means handing over the whole folder and resolving relative paths — and getting that half-right shows you a black model rather than an error. That is a different tool, not a checkbox on this one. A .glb that names its textures or buffers by URI instead of embedding them is refused for the same reason — and refusing it also means nothing you open here can make your browser fetch from a third party.
- Does it open Draco or Meshopt compressed files?
- Yes, and KTX2 textures too. Draco and KTX2 each fetch their own decoder from this site, never a third-party CDN, and only when your file actually needs it — a model using neither downloads neither. Meshopt's decoder is small enough to ship as part of the viewer itself, so there is nothing extra to fetch for it at all.
- What does the triangle count include?
- What the GPU is asked to draw. An instanced mesh counts once per instance, because that is the real cost, and a geometry shared by two meshes counts twice for the same reason. It is a render figure, not a file-contents figure.
- Why is the texture size different from the file size?
- The texture figure is the compressed weight stored inside the GLB, read from the file's own buffer layout. The rest of the file is geometry, animation and JSON. If the two are close, your model's weight is textures, and resizing them is the fastest thing you can do about it.
- The model appears but the details panel says an extension is not supported. Is it broken?
- Not necessarily. Unknown extensions are skipped rather than fatal, so the model still renders — just without whatever that extension added, such as a transmission or iridescence effect. The panel lists them so you know what you are not seeing.
- Can I download a picture of the model?
- Yes — Download PNG captures the current view exactly as framed, with the option of a transparent background and of rendering at twice the on-screen size, which is usually what you want for a product thumbnail.
- There is no animation bar on my model.
- Then the file contains no animation clips. The bar is hidden rather than greyed out, because a disabled transport reads as something broken instead of something absent. The Animation group in the details panel says the same thing in words.