How to open an STL file
- Click Open STL Viewer.
- Drag & drop your
.stlfile into the viewer. - Rotate, zoom, and inspect your model before printing or sharing.
Tip: STL usually contains geometry only (no textures). If you need colors/materials, consider GLB/GLTF.
What is an STL file?
STL (Stereolithography) is a widely used 3D file format for 3D printing and rapid prototyping. It represents surfaces using triangles and typically does not include materials, textures, or units.
STL tips for 3D printing
Units
STL files often don’t store units. If a model looks too big/small, it may be a mm vs inch issue.
STL files often don’t store units. If a model looks too big/small, it may be a mm vs inch issue.
Manifold checks
Non-manifold geometry can cause printing issues. Check for holes or flipped normals if something looks off.
Non-manifold geometry can cause printing issues. Check for holes or flipped normals if something looks off.
High-poly files
Large STL files can be heavy. If possible, decimate the mesh before sharing or viewing on mobile.
Large STL files can be heavy. If possible, decimate the mesh before sharing or viewing on mobile.
Also view other 3D formats
OBJ Viewer
Meshes + MTL textures
Meshes + MTL textures
STEP Viewer
CAD assemblies/solids
CAD assemblies/solids
FBX Viewer
Animation pipelines
Animation pipelines
GLTF Viewer
Web-ready scenes
Web-ready scenes
GLB Viewer
Binary GLTF
Binary GLTF
FAQ
Is this STL viewer free?
Yes — you can open and preview STL files directly in your browser for free.
Does STL include colors or textures?
Usually no. STL primarily stores geometry. For materials/textures, use formats like OBJ (with MTL) or GLB/GLTF.
Can I share a link to the STL viewer?
Yes. Share the viewer URL after loading a model, or link to /3d-viewer?format=stl.