Free STL to GLB Converter

How to convert STL to GLB

Step 1. Drop your STL file on the converter above, or choose it from your device.

Step 2. Look at the preview. If the model lies on its side, change the up direction to match your file.

Step 3. Check the unit. STL does not say which unit it uses. Slicers read it as millimeters, so that is the starting choice here. Choose the unit your model was made in, and the GLB file is scaled to meters. The size next to the download button changes with it.

Step 4. Press the download button. The GLB file is saved to your device, named like your original with .glb at the end.

Showing a printable part on the web

STL files come from CAD tools and slicers, and most viewers on the web do not read them. A GLB opens in web viewers, in AR apps on Android, and in game engines. Converting lets you share a part with someone who has no CAD program.

Two things change on the way. An STL uses Z as up and is read as millimeters, while a GLB uses Y as up and meters. The converter turns the model upright and scales it for you, so a 50 mm part becomes 0.05 meters. If your STL was made in another unit, choose it in the list.

What survives the conversion

Shapes. Binary and text STL files are both read. Every triangle is written, with normals and UV coordinates.

Colors and materials. STL has no colors, so the model starts out plain. Materials are written as standard glTF materials: color, color texture, normal map, glow, and transparency.

Textures. STL has no textures. Pictures are packed into the file.

Animation. STL cannot hold animation. Animation clips are kept.

Units and direction. STL does not say which unit it uses. Slicers read it as millimeters, so that is the starting choice here. The file is in meters, with Y pointing up.

If something looks wrong

If the model lies on its side, change the up direction to Y.

A model with holes or flipped faces was already broken when it was exported. Repair it with your slicer's repair tool before you print.

An STL has no colors or pictures, so the GLB is plain white. That is how the file is, not a fault in the conversion.

If your app shows the model sideways, check its import axis. A GLB has Y pointing up.

If your browser cannot draw 3D, there is no preview, but the conversion still works.

Your file stays on your device

The converter reads your STL file in the browser and writes the GLB file there too. Nothing is uploaded, and the page does not load anything the file points to, other than files you choose yourself. The page counts a visit like any other page, but it never sees the file's name or contents.