Convert OBJ to STL Online
OBJ files are a simple, widely supported 3D mesh format with a companion MTL material file. Converting to STL gives you 3D printing, CAD previews.
How to convert OBJ to STL
- Upload your OBJ file. Drag it onto the box above or click to browse. Files up to 200 MB are accepted.
- Choose STL as the output. The target format is pre-selected on this page — just press “Convert now”.
- Download the result. Conversion runs on our own server and the download starts as soon as it is ready. Your files are deleted automatically.
Why convert OBJ to STL?
OBJ is a simple, widely supported 3D mesh format with a companion MTL material file. STL is the standard format for 3D printing, storing surface geometry only. That difference is exactly why converting between them is so common: STL is the better choice for 3D printing, CAD previews.
OBJ vs STL: key differences
| OBJ | STL | |
|---|---|---|
| File type | mesh | mesh |
| Typical use | 3D printing, game assets, model exchange | 3D printing, CAD previews |
| Compatibility | Universal mesh support; no animation. | Universal in slicers; no colour or materials. |
Tips for a clean OBJ to STL conversion
- Universal mesh support; no animation.
- Use the highest-quality source OBJ you have — converting a compressed file again cannot restore lost detail.
- If you only need a smaller file, try a lower resolution or bitrate instead of a different format.
- Keep the original OBJ until you have checked the converted STL opens the way you expect.
Frequently asked questions
How do I convert OBJ to STL?
Upload your OBJ file to the converter on this page, make sure STL is selected as the output format and click “Convert now”. When the conversion finishes the download starts automatically.
Is this OBJ to STL converter free?
Yes — it is completely free and needs no account. Files up to 200 MB are accepted, and heavy use is rate-limited so the service stays available for everyone.
Will converting OBJ to STL reduce quality?
STL uses its own compression, so the converted file is re-encoded. Quality loss is minimal at sensible settings, but keep the original OBJ if you may need to convert again later.
What is a OBJ file?
OBJ is a simple, widely supported 3D mesh format with a companion MTL material file. Its technical name is Wavefront OBJ and it is typically used for 3D printing, game assets, model exchange.
What is a STL file?
STL is the standard format for 3D printing, storing surface geometry only. Its technical name is Stereolithography and it is typically used for 3D printing, CAD previews.
Can I convert OBJ to STL on my phone?
Yes. The converter runs in the browser on Android, iOS, Windows, macOS and Linux — no app installation is required.
Are my files kept on the server?
No. Uploaded files and converted results are deleted automatically a short time after the conversion finishes.