Free STL to OBJ Converter
Lightning-fast STL to OBJ conversion — 100% in your browser. Your files never leave your device. Free, no watermark, no sign-up.
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Supports GLB, GLTF, OBJ, STL, FBX, PLY
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STL vs OBJ
See what transfers when converting between these two formats.
| Feature | STL | OBJ |
|---|---|---|
| Geometry | ||
| Textures | ||
| Materials | ||
| Animation | ||
| Rigging |
All features supported by STL are preserved in OBJ.
Why convert STL to OBJ?
Edit STL scans in DCC tools
Blender, ZBrush, Maya, and 3ds Max all read OBJ natively. STL support varies — OBJ is the safer import format for editing workflows.
Sculpt and retopologize
ZBrush and 3D-Coat prefer OBJ for sculpting and remeshing. Convert STL scan data before sculpt cleanup workflows.
Add materials and UVs
STL has no materials or UVs. Convert to OBJ to get a format that supports both — add them in Blender and re-export.
Tips for STL → OBJ
OBJ enables materials
OBJ supports a basic material library (.mtl). After conversion, you can add an .mtl file to define colors and textures.
Binary STL converts faster
Binary STL is roughly 4x smaller than ASCII STL and parses faster. If your STL is ASCII, re-export from your CAD tool as binary first.
Multiple STLs become groups
If you convert multiple STLs, Fast3D processes them one at a time. To merge meshes, do it in Blender after conversion.
Check normals after conversion
STL does not store vertex normals explicitly; OBJ does. Fast3D computes normals during conversion — verify they look correct in your viewer.
Common issues when converting STL to OBJ
OBJ has no materials
Fix
STL has no material data. The converted OBJ references a default .mtl file. Edit the .mtl in any text editor to add a diffuse color, or assign materials in Blender after import.
Model imports sideways or upside-down
Fix
STL is often Z-up; OBJ is unspecified. Some importers flip the model automatically, others do not. If your model lands wrong, rotate 90° around X in your DCC tool.
File is large
Fix
STL meshes are typically dense. Decimate in Blender before converting, or downsample the STL using MeshLab's Quadratic Edge Collapse filter.