GLB Viewer — View GLB & glTF Files Online

A GLB file is the binary form of glTF 2.0: one file that packs a 3D model's meshes, materials, textures and animations together. The Khronos Group published glTF 2.0 in 2017, and in 2022 it became an international standard, ISO/IEC 12113. That is why a .glb from Blender, an AI model generator or a 3D scanning app opens in this GLB viewer, in web pages and in most game engines.

A .glb viewer only needs to read the file and draw it. Editing, re-texturing and exporting to other formats are jobs for a 3D editor.

GLB vs glTF: One File or a Folder

The same model can be saved in two ways. A .gltf file is readable JSON that points to separate files: a .bin file with the geometry and one image per texture. A .glb packs the JSON, the binary data and the images into a single file, which is easier to email, upload and keep together.

Inside a GLB: Header, JSON and Binary Chunks

The 12-byte header

Every GLB starts with the letters glTF, a version number and the total file length. The viewer checks these bytes first, which is how it can tell you when a "GLB" is really an FBX or a glTF 1.0 file.

The JSON chunk

Next comes a block of JSON describing the scene: meshes, materials, textures, animations and how many vertices each part has. The model report is read from here, so the counts appear before anything is drawn.

The binary chunk

Last comes the binary data: vertex positions, normals, animation keyframes and usually the texture images themselves, stored as PNG, JPEG, WebP or KTX2.

Opening a model is half the job. The other half is knowing whether it is ready for where it is going: a web page, a phone, an AR app or a game. This GLB viewer reads the numbers that answer that question.

Vertices, Triangles and Meshes

Triangles are the clearest measure of how heavy a model is to draw. A product model for a web page usually stays in the tens of thousands; a scanned statue can run into the millions and stutter on a phone. Vertices shared by several parts are counted once, so the figure matches what is stored in the file.

Textures: Where Most of the Bytes Go

Most people expect complex geometry to make a GLB big. It rarely does. The Info tab shows a bar that splits the file into textures, geometry, animation and the rest, and for most static models the texture slice dominates. The Avocado sample has just 682 triangles but weighs 7.73 MB, almost all of it three 2048 × 2048 images.

We measured 13 GLB files from the Khronos glTF Sample Assets with this viewer's own parser. Textures were a median 95% of the file. Only the animated characters and a 109,000-triangle toy car were mostly geometry. The table below has the full numbers.

Animations and Morph Targets

Animated files list every clip with its length. Pick a clip, pause it, scrub the timeline or slow it to a quarter of its speed to check a walk cycle frame by frame. Skins and morph targets, used for characters and facial expressions, are counted in the report as well.

Compression Extensions It Decodes

Many GLBs are compressed, and a viewer that cannot decode them shows nothing at all. This one handles the common extensions:

• Draco (KHR_draco_mesh_compression) shrinks geometry heavily but needs a decoder before the model can be drawn.
• meshopt (EXT_meshopt_compression) compresses geometry and animation and decodes very quickly.
• KTX2 (KHR_texture_basisu) keeps textures in a GPU-ready format that uses less video memory.
• WebP (EXT_texture_webp) makes texture files smaller, and browsers decode it natively.

Each decoder downloads only when a file declares its extension, so a plain GLB never pays for it.

A .gltf file on its own is only the JSON description. The geometry sits in a .bin file next to it, and the textures in image files, often inside a textures folder. Give this glTF viewer all of them at once: select them together in the file dialog, or drag the whole folder onto the viewer.

The viewer matches each file to the path written in the .gltf, so the folder structure is respected. If the .bin is missing, it tells you its exact name instead of failing silently. If a texture is missing, the model still opens and the missing files are listed, so you know which ones to look for.

When a model refuses to load, the cause is almost always one of these five, and this GLB viewer names it instead of showing a blank screen.

It Isn't Really a GLB

FBX, OBJ and STL files are sometimes renamed to .glb in the hope that it helps. It doesn't: the bytes are still a different format. The viewer reads the first bytes and says what the file really is, so you can export it again as GLB from Blender or the program that made it.

The Model Is Black, Grey or Missing Textures

A .gltf whose image files were left behind shows plain grey or white surfaces. A model that looks black usually needs light: switch on Studio lighting in the Scene tab or raise the exposure.

It's Tiny, Huge or Lying on Its Side

glTF measures in metres with +Y pointing up. A model exported in millimetres arrives 1,000 times too big, and one built around a different up axis lies on its side. The viewer frames every model automatically so it is always in view; fix the scale or the axis when you export.

It's a glTF 1.0 File

Files exported before 2017 may be glTF 1.0, which current tools no longer read. Cesium's open-source gltf-pipeline can upgrade most of them to glTF 2.0.

The Page Slows Down or Crashes on a Phone

Phones share a small amount of memory between the browser and the graphics chip. A 120 MB scan with 8K textures can use all of it, which is why the limit on phones is 50 MB. Open large files on a computer, or shrink the textures first.

A GLB viewer draws in real time, many frames per second, using physically based rendering and a studio environment for reflections. Blender's Cycles renderer traces rays of light for seconds or minutes per image, with soft shadows and light bouncing between surfaces. The materials are the same; the lighting is not.

Colour can shift too. This viewer uses Khronos PBR Neutral tone mapping, which is designed to keep product colours accurate, while other tools may apply a filmic look. If a model looks too dark or too bright, adjust the exposure in the Scene tab rather than editing its materials.

The camera button saves exactly what you see as a PNG image. Choose 1×, 2× or 4× the size of the viewer for a sharp picture on high-resolution screens, and tick Transparent background to drop the studio backdrop. The soft floor shadow stays, so the model sits naturally on any page colour.

That makes this GLB viewer a quick way to turn a GLB into a PNG for a product listing, a document, a thumbnail or a portfolio. To make the image lighter afterwards, compress the PNG or convert it to WebP, and resize it to the exact dimensions a site asks for.

With this one, yes. The file is read and rendered inside your browser tab; it is never uploaded and nothing about it is stored. Even a .gltf that points to texture addresses on another website is not allowed to fetch them, so opening a model sends no requests on its behalf.

The only extra downloads are the viewer's own components: the 3D engine, plus the Draco or KTX2 decoder when a compressed file needs one. They are program code, identical for everyone, and contain nothing of yours. You can check this yourself in your browser's developer tools, under Network, while a model opens.