Free 3D File Converter
OBJ to STL Converter
Drag in a .obj file, see it in 3D, and download a clean .stl in seconds — right in your browser. No upload, no sign-up, no quality loss.
- ✓ 100% free
- ✓ Private — nothing uploaded
- ✓ Instant, in-browser
- ✓ No sign-up
No 3D file handy? Try a classic model
Click any model to load it into the converter above and convert it instantly.
Sample models from the public common-3d-test-models repository.
.obj in Modeling, rendering, games .stl out 3D printing & CAD export How to convert OBJ to STL
Drop your .obj file into the box above, click to browse, or pick a classic sample model. It loads instantly — nothing is uploaded.
Your model renders in an interactive 3D viewer. Drag to rotate and confirm it is the right mesh.
Click Convert to STL and download your .stl file — ready for Cura and any STL app.
OBJ vs STL: what's the difference?
| Feature | OBJ | STL |
|---|---|---|
| Geometry (mesh) | ✓ | ✓ |
| Color | ✓ | — |
| Materials | ✓ | — |
| UV textures | ✓ | — |
| Best for | Modeling, rendering, games | 3D printing & CAD export |
| File size | Larger (readable text) | Compact (binary) |
What is a OBJ file?
OBJ is one of the most widely supported 3D formats in existence. Beyond geometry it can reference materials through a companion .mtl file and store UV coordinates for textures, which makes it a go-to format for modeling, rendering and game engines.
What is a STL file?
STL describes a 3D surface as a simple mesh of triangles. It is the universal language of 3D printing and CAD export, supported by every slicer and printer — but it stores only raw geometry, with no color, material or texture data.
Why convert OBJ to STL?
Wavefront OBJ (.obj) is oBJ is one of the most widely supported 3D formats in existence. Beyond geometry it can reference materials through a companion .mtl file and store UV coordinates for textures, which makes it a go-to format for modeling, rendering and game engines.
Converting to STL keeps the geometry but intentionally drops color, materials and UV textures — exactly what you want for 3d printing & cad export. STL describes a 3D surface as a simple mesh of triangles. It is the universal language of 3D printing and CAD export, supported by every slicer and printer — but it stores only raw geometry, with no color, material or texture data.
This converter does the translation locally, in your browser: your file is read into a real 3D engine, shown so you can confirm it, then re-exported as a standards-compliant STL — no server, no account, no upload queue.
When to convert OBJ to STL
3D printing & slicing
STL drops straight into slicers like PrusaSlicer, Cura and Bambu Studio for a clean, printable mesh.
Game & real-time assets
Engines such as Unity and Unreal prefer 3d printing & cad export formats. The converted STL fits straight into asset pipelines.
Editing & remeshing
Need to sculpt, retopologize or repair a model? Convert to STL so it opens in the tools that handle that best, then export again.
Sharing & interchange
STL is widely supported, making it a safe format for handing a model to a teammate, client or another application.
Your STL works everywhere
The exported STL imports cleanly into the major tools for 3d printing & cad export:
- Cura
- PrusaSlicer
- Bambu Studio
- Blender
- Fusion 360
Tips for the best OBJ → STL results
- • Repair scans first. If your OBJ came from a 3D scanner, run a quick mesh repair (Blender or MeshLab) to close holes before converting.
- • Expect a size change. STL is compact (binary), so the output size may differ from your OBJ — that's normal.
- • Check scale & orientation. Different tools assume different units. After importing the STL, confirm the model's size and up-axis match your scene.
- • Keep the original. Conversion is one-way here, so hold on to your source OBJ in case you need to re-export with different settings.
Frequently asked questions
Is this OBJ to STL converter free?
Yes — completely free, no sign-up and no watermark. The conversion runs entirely in your browser using WebGL, so your file never leaves your computer and there is no upload wait.
Does converting OBJ to STL lose quality?
The geometry is preserved exactly. STL does not store color, materials and UV textures, so that information is dropped during conversion — which is expected and usually desirable for 3d printing & cad export.
What is the largest OBJ file I can convert?
Because everything runs locally, the limit is your device's memory rather than an upload cap. Most models up to a few hundred MB convert smoothly on a modern laptop.
Where can I use the converted STL file?
STL is 3d printing & cad export. The exported file imports cleanly into Cura, PrusaSlicer, Bambu Studio, Blender and other STL-compatible tools.
Is it safe to convert private or proprietary models?
Yes. Nothing is uploaded — the file is read and converted on your own device, then the STL is generated locally for download. Your model stays private.