GLB to STL

Convert GLB to STL and print it

This page converts GLB to STL in your browser. Drop a .glb file, check it in the preview, and download an STL your slicer can open. The file is not uploaded; it is converted on your own device.

GLB files come from game asset stores, photogrammetry and phone scanning apps, AI model generators, and sites that show 3D models on the web. When you want to print one of those, the slicer usually wants STL. The conversion itself is quick; the work is in checking that a model built to be looked at can also be printed.

How to convert GLB to STL

1. Drop the .glb file onto the converter. For a .gltf with separate .bin and image files, drop them all together.

2. Check the preview and the bounding-box size in the info panel. If the model is animated, the STL takes the rest pose stored in the file, which for a rigged character is usually a T-pose.

3. Leave “Fix up axis” on to have the model stand on the bed.

4. Click Convert and download the binary STL. Then scale it in your slicer.

To keep the shape editable in a modeling program instead, try GLB to OBJ.

What changes when GLB becomes STL

GLB holds a whole scene. STL holds one surface made of triangles. Everything that isn't shape is left behind:

Meshes

Merged into one. Every mesh in the GLB is combined in world space, with its position, rotation and scale from the scene applied, so the parts sit where they did in the preview.

Textures and colors

Dropped. A scanned object that looked photo-real becomes a single plain surface, because the realism was in the texture, not the geometry.

Materials and UVs

Dropped. STL can't store them, and slicers don't use them.

Animation and rigs

Dropped. A rigged character is written in the rest pose stored in the file, which for a rigged character is usually a T-pose.

Compression

Draco- and Meshopt-compressed GLBs are decoded first, so a small compressed GLB can produce a much larger STL.

Why your model is 0.2 mm tall

glTF measures everything in meters. Slicers read the numbers in an STL as millimeters. The converter copies coordinates without rescaling, so a figure that is 0.2 meters tall in the GLB arrives in the slicer 0.2 mm tall: a speck you may not even see on the bed.

The fix is a scale factor of 1000. In most slicers you can enter 100,000% as the scale, or type the height you want directly into the size field, which is often easier since a game character probably shouldn't be printed at life size anyway. Some slicers notice a suspiciously small model and offer to convert it from meters for you; if yours asks, accept.

Not every GLB follows the meters rule. Files converted from FBX are often in centimeters, so check the bounding box in the info panel before converting and work out the factor from there.

Printing a model from an AI 3D generator

Image-to-3D and text-to-3D tools such as Tripo, Meshy and Hunyuan3D usually hand you a GLB: one mesh, with its colors baked into a texture. Converting it to STL is often the quickest way to print one, and it works like any other GLB.

These models tend to come out about one unit across, which a slicer reads as about one millimeter. Rather than working out a percentage, type the height you want into the slicer's size field.

The colors stay behind: they live in the texture, and STL has none. What prints is the shape. For a multicolor print, paint the regions in a slicer that supports it, such as Bambu Studio or PrusaSlicer.

Look at the thin parts in the preview before you slice. Ears, antennae, fingers and accessories guessed from a single image are often thinner than a nozzle can lay down, and the back of the model, which the generator could not see, is where holes and odd shapes turn up.

Up axis: standing on the bed

GLB is Y-up. STL and slicers are Z-up. Without a correction, a character would arrive lying on its back. “Fix up axis” is on by default and rotates the model 90 degrees so it stands upright on the build plate. If you'd rather print it lying down, you can still turn it off, or rotate it in the slicer.

Models made for screens, not printers

Game and web models only have to look right from the camera. A printer needs a closed, solid shape with real thickness. The converter does not repair meshes, so look out for these before you slice:

Open, non-manifold meshes

Missing faces under the feet or inside the mouth, edges shared by more than two faces. The slicer may fill them wrongly or leave gaps. Run your slicer's repair or a mesh repair tool first.

Floating pieces

Eyes, teeth, buttons and accessories are often separate meshes that merely touch the body. They stay in place in the STL but may need supports, or to be joined in a 3D editor.

Paper-thin parts

Hair cards, leaves, capes and clothing are frequently single planes with no thickness. They slice to nothing. Add thickness in a 3D editor.

Detail that lives in the texture

Scales, wrinkles and engraved text in a game asset are often painted or in a normal map, not in the mesh. They won't print.

Scan noise

Photogrammetry models can have stray floating fragments and a ragged base. Delete the fragments and flatten the bottom before printing.