Free 3D converter

Convert GLB to STL

Drop a GLB file and download it as STL, scaled and set on the build plate. The conversion runs in your browser, so the file never leaves your device. It keeps the exact shape and a real size in millimetres.

Free, no sign-up, and your file stays on your device.

Drop a GLB file here

Converted to STL in your browser. Nothing is uploaded.

GLB, glTF, OBJ, STL, PLY, FBX or 3MF, up to 300 MB. Add .mtl, .bin and texture files alongside.

What carries over from GLB to STL

Checked against what the converter writes, not just what the formats allow.

Shape (triangles): Kept exactly
UV coordinates: Dropped: STL can't store it
Colour texture: Dropped: STL can't store it
PBR maps (roughness, metalness, normal): Dropped: STL can't store it
Vertex colours: Dropped: STL can't store it
Animation: Dropped: STL can't store it
Separate parts: Dropped: STL can't store it
Size and units: Metres become millimetres, or the model is scaled to the height you set (100 mm by default).
Up direction: Turned Z up and set flat on the build plate.

How to convert GLB to STL

Add your GLB
Drop the .glb file or choose it from your device.
Check the preview
Turn the model, check its triangle count, and set the height you want to print in millimetres.
Download the STL
The .stl is written in a second or two for most models.

When to convert GLB to STL

To 3D print it
Every slicer reads STL. The GLB becomes a plain list of triangles, sized in millimetres and ready to slice.
To send it to a print service
Print bureaus and online quote tools ask for STL more than anything else.

The two formats

GLB

Binary glTF 2.0

GLB is the single-file, binary form of glTF 2.0, the open format the Khronos Group published in 2017 for delivering 3D assets. Mesh, materials, textures and animation all travel in one file.

Usually comes from: AI 3D generators (including PhotoGenius), Sketchfab downloads, web 3D projects and game asset stores
Opens in: Blender, Godot, three.js and most web viewers, Android's Scene Viewer, Bambu Studio and UltiMaker Cura, Unreal's glTF importer, and Unity with the glTFast package
Units: Metres
Up axis: Y up

STL

Stereolithography

STL was created by 3D Systems in 1987 for its stereolithography printers. It stores a surface as a list of triangles and nothing else: no colour, textures or units.

Usually comes from: print libraries such as Printables and Thingiverse, CAD exports and 3D scanners
Opens in: every slicer (Bambu Studio, PrusaSlicer, OrcaSlicer, UltiMaker Cura and others) and most 3D apps
Units: None recorded (read as millimetres by slicers)
Up axis: Z up by convention

Need a model to convert?

Make one with AI from a photo or a sentence, then download it as GLB and convert it here.

Questions

Something else? Ask us and a person will answer.

Is this GLB to STL converter free?

Yes. There is no account, watermark or limit on conversions. It accepts files up to 300 MB; how large a model your browser can handle depends on your device's memory.

Is my file uploaded?

No. The conversion runs in your browser with the open-source three.js loaders and exporters, so your GLB never leaves your device.

Why is my STL the wrong size in the slicer?

GLB is measured in metres and slicers read STL as millimetres. AI-generated models are usually around a metre across, so the converter scales them to a height you choose (100 mm by default). Turn that off to keep the real size.

Will colours and textures be kept in the STL?

No. STL stores only triangles. For a full-colour print, keep the GLB and colour it in your slicer, or export to OBJ with its texture.

Is the model watertight and printable?

The converter keeps the shape exactly; it doesn't repair it. Slicers fix small holes automatically. For meshes with many open edges, run them through your slicer's repair or Blender's 3D Print Toolbox first.

Can I make a 3D model from a photo instead?

Yes. PhotoGenius turns a photo or a text prompt into a textured GLB with Rodin Gen-2.5, Rodin Gen-2.5 Fast, Tripo H3.1, TRELLIS.2, Rodin Gen-2 or Hunyuan3D 3.1, which you can then convert here. See Image to 3D model.

Turn a photo into a 3D model

Rodin Gen-2.5, Rodin Gen-2.5 Fast, Tripo H3.1, TRELLIS.2, Rodin Gen-2 or Hunyuan3D 3.1 builds a textured GLB from one image. The price shows before you run it.

Make a 3D model About the 3D generator