Free GLB Viewer — Open GLB & glTF Files

Open .glb and .gltf files free in your browser, in colour and standing upright. Measure the model, fix its scale, repair it and export STL or 3MF to print it.

Open a GLB — in colour, the right way up.

GLB is how 3D gets delivered on the web and in AR, and most quick previews hand it back grey or lying on its side. Drop one here and it opens in colour, standing upright on a build plate, ready to measure and to print, if that is where it is headed.

Free to use · Runs in your browser · No upload wait

A delivery format, opened properly

A GLB usually arrives from somewhere else: a scan, a marketplace, an AR asset, a generator. The questions that follow are all about whether it is usable.

It keeps its colours

Each vertex takes its colour from the material’s base-colour texture where there is one, or a vertex-colour attribute, or the flat material colour, so a catalogue or scanned model looks like itself instead of turning grey the moment it is opened.

And it stands upright

glTF is Y-up; a printer’s build plate is Z-up. OwlCAD rotates the model on the way in so it stands rather than lying on its side, and applies the exact inverse on export, so a round-trip through OwlCAD comes back identical.

Fix the scale it arrived at

glTF is conventionally authored in metres, so a web asset often lands 1000× small. Reinterpret it as millimetres, centimetres, inches, or metres in one tap, with the resulting dimensions previewed before you accept, then type exact values.

Measure it properly

Edge lengths, hole radii and diameters, true arc lengths, face areas, angles, and the smallest gap between two parts, plus bounding size, volume and triangle count.

Make it printable

Web and AR assets are rarely print-ready. Run the print check for thin walls, overhangs, and watertightness, repair the mesh, hollow it, auto-orient it, and see what it will weigh and cost in filament.

Convert it onward

Export STL or 3MF for a slicer, OBJ or GLB for other 3D software, or SVG and DXF of a 2D projection for a laser cutter, all at true millimetre scale.

Drop in a GLB and look at it properly

No download, no account needed. It opens in your browser, in colour.

What happens to your file

It opens on your device, it is saved to your workspace as you work, and it exports back out in the format your slicer wants.

No upload queue

Your browser reads and renders the model itself, so it appears as soon as you drop it in — you are never queued behind anyone else’s upload, and the file does not travel anywhere before you can see it.

Saved, not discarded

Most online viewers forget your file the moment you close the tab. OwlCAD keeps the model in your own workspace and syncs it as you work, so it is still there when you come back to this browser. Create a free account and it follows you to any device, and your projects dashboard lets you delete anything you no longer want.

Exports to a real file

When you are done, export STL, 3MF, OBJ, GLB or STEP — the format your slicer or your colleague actually needs, not a project file that only opens here.

Frequently asked questions

How do I open a GLB or glTF file?

Drag the .glb onto the build plate — it renders immediately. Your browser reads and displays the file itself, so there is no upload to wait for, no queue, and no account needed to look at it.

Will it keep the model’s colours?

Yes, in most cases. OwlCAD takes each vertex’s colour from the material’s base-colour texture where there is one, otherwise from a vertex-colour attribute, otherwise from the flat material colour — so a catalogue or scanned model arrives looking like itself rather than grey. Full PBR materials, animation, and rigging are not carried over: this is a modeling tool, and what survives is the shape and its colour.

Why is my model lying on its side in other tools but upright here?

glTF is Y-up and OwlCAD is Z-up like a printer’s build plate, so the import rotates the model to stand it up. The export applies the exact inverse, which means a GLB round-trip through OwlCAD comes back identical rather than progressively tipped.

My GLB opened far too small or too large — why?

glTF files are conventionally authored in metres, and OwlCAD works in millimetres and treats one glTF unit as one millimetre in both directions so a round-trip stays exact. A model authored in metres therefore arrives 1000× small. The bar shown on import reinterprets the file in one tap and previews the resulting dimensions, so you can pick the right reading before accepting it.

Can I convert GLB to STL or 3MF for printing?

Yes. Open the .glb and export STL, 3MF, OBJ, or GLB — and because this is a full editor rather than a converter, you can scale it to a real size, hollow it, repair non-watertight geometry, and run the print check first, which is usually what a web or AR asset needs before it will print.

Is the GLB viewer free?

Yes. Viewing, measuring, editing, repairing, and exporting are free forever, with no watermark and no file limit. Only AI generation is part of OwlCAD Pro.

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