Can Unity Open STL Files? How to Import Them
Unity is a widely used game engine for mobile, desktop, console and XR games, and it imports models by copying them into the project's Assets folder.
Short answer · Convert first
Not directly. Unity doesn't import STL, so convert the file to OBJ first and import the OBJ.
Open the STL to OBJ converterGetting an STL file into Unity
- 1Check the fileFind out what units the part was designed in. Almost every printable STL is in millimetres, but the file itself doesn't say.
- 2Convert STL to OBJDrop the file into our STL to OBJ converter. It runs in your browser, so the model never leaves your computer.
- 3Import into UnityDrag the .obj (and its .mtl) into the Project window.
- 4Check scale and orientationUnity works in metres and is Y-up. STL files are unitless (slicers assume millimetres), so the size depends on what the exporter assumed.
- 5Check materials and animationSTL carries no colour or materials, and no animation. Look at the model under a neutral light before you build on it.
What comes through
| Shape | Yes, always. |
| Colours and materials | Yes: basic materials in a separate .mtl file. |
| Textures | STL doesn't store texture images. |
| Animation | No: OBJ has no animation. |
Things to watch for
- Unity's importer doesn't read STL. Converting to OBJ gives you the same triangles in a format Unity opens directly.
- Select the imported model and check Scale Factor and Convert Units in the Model tab of the Inspector before placing it in a scene.
Questions
- Does Unity support STL files?
- Not directly. Unity doesn't import STL, so convert the file to OBJ first and import the OBJ.
- Why is my STL model the wrong size in Unity?
- STL files are unitless (slicers assume millimetres), while Unity works in metres. Select the imported model and check Scale Factor and Convert Units in the Model tab of the Inspector before placing it in a scene.
- What is the best 3D format for Unity?
- FBX and OBJ are the most reliable choice for Unity. If you have a choice when exporting, pick FBX over STL.
Menu names follow Unity Technologies's current release. Check the official Unity documentation if your version differs.
Written with AI assistance by the Renderlyst team in October 2026. Format support reflects each app's current release as we understand it, and we link the official documentation so you can confirm it for your version. Spotted something out of date? Email alishbakhalid766@gmail.com.