GLB to STL Converter

Print models from AI generators, Sketchfab or the web: GLB to STL with the size converted from metres to millimetres and the model standing upright on the plate.

  • Files stay on your device
  • Free, no sign-up
  • Units and up axis handled
  • Batch and .zip

Drop a GLB file to convert

One file, many, or a .zip

In: STL · STEP · IGES · OBJ · 3MF · GLB · glTF · PLY · FBX · DAE · 3DS · AMF · VRML · ZIP

Converted on your device. Nothing is uploaded.

    How to convert GLB to STL

    1. Drop your GLB files

      Drop .glb files, including Draco, Meshopt and KTX2 compressed ones.

    2. Check the preview

      The model appears at the size and orientation it will have. Fix the file units, up axis or size under Size, units and orientation if needed.

    3. Choose STL options

      Binary STL by default (smallest, read everywhere). Tick ASCII only if an old tool asks for text STL.

    4. Convert and download

      One file downloads straight away. A batch gives a download per file and one .zip of all of them.

    What carries over from GLB to STL

    Worked out from what each format can store and what this converter writes. Nothing is changed silently: the preview shows the size and orientation before you download.

    Geometry Every triangle is kept at full precision.
    Color Dropped: STL cannot store color.
    Units Converted from metres to millimetres, so it keeps its real size. A 0.05 m part comes out 50 mm.
    Orientation Turned from Y up to Z up, so it stands on the plate in a slicer.
    Objects Merged into one surface: STL has no objects.
    Animation Dropped: the model is written in its rest pose.

    GLB to STL: what actually happens

    AI 3D generators and web tools hand out GLB; slicers want STL. The converter reads the GLB (including Draco and Meshopt compressed ones), turns glTF's metres into millimetres and its Y up into Z up, and merges every mesh into one STL. A 0.12 m figure becomes a 120 mm STL, standing on the plate.

    Textures, materials and animation are dropped, because STL stores only shape. AI models in particular are often not watertight; check the result in the STL viewer and run Mesh Repair if it reports open edges.

    GLB at a glance

    glTF 2.0 binary · .glb

    Stores
    Meshes, PBR materials, textures, animation and scenes in one binary file
    Color
    Full: textures, base colors and vertex colors
    Units
    Metres, fixed by the glTF spec
    Up axis
    Y, fixed by the spec
    File size
    Compact; Draco or Meshopt compression shrinks meshes 5 to 10 times
    Opens in
    Web viewers, Blender, Windows, Android Scene Viewer, Godot, Unity and Unreal importers

    glTF 2.0 is the Khronos Group's "JPEG of 3D", and GLB is its single-file binary form. It is what AI 3D generators, Sketchfab downloads and web apps hand out, and it is the only common format whose units (metres) and axes (Y up) are fixed by the spec.

    Open GLB files in the viewer

    STL at a glance

    Stereolithography (Standard Triangle Language) · .stl

    Stores
    Loose triangles: three corners and a normal each, binary or ASCII
    Color
    None in the standard
    Units
    None written; slicers assume millimetres
    Up axis
    Z, the slicer convention
    File size
    50 bytes per triangle in binary, about 5 times that as ASCII
    Opens in
    Every slicer, CAD tool and 3D app

    Created by 3D Systems in 1987 for the first stereolithography printers, STL is still the format every slicer and print service accepts. It describes a surface as a list of independent triangles, with no shared vertices, units, colors or scene structure.

    Open STL files in the viewer

    Tips for GLB to STL

    Arbitrary size

    AI generators often export a model a metre or two across. Scale it in the converter (set the height in mm) or in the slicer.

    Keep the color

    For a multi-color printer, use the AMS converter instead: it turns textures into filament colors.

    Animated GLB

    The STL is taken from the rest pose.

    GLB to STL FAQ

    Why is my STL from GLB so big or so small?
    GLB is in metres. The converter converts to millimetres, so the STL has the size the GLB claimed. Many AI models claim an arbitrary size; set a height in mm under Size, units and orientation.

    Does GLB to STL keep textures?
    No. STL stores geometry only. Use 3MF with the AMS converter for filament colors.

    Can it read Draco-compressed GLB?
    Yes. Draco, Meshopt and KTX2 textures are all supported.

    Is the converter free? Are there limits?
    Free, with no sign-up, watermark or file count limit. Batches and files of a few hundred MB work on most laptops; the only limit is your device's memory.

    Are my files uploaded?
    No. Files are read and written by JavaScript and WebAssembly in your browser and never sent to PrintPal. The STEP and IGES reader is the only extra download, once, from a public CDN.