OBJ to STL converter
Drop an OBJ file and get an STL back in seconds. OBJ is plain text, read almost everywhere, used mostly for older 3D software and CAD-adjacent tools. STL is triangles only, the usual choice for 3D printing slicers. The conversion runs entirely in your browser, so your file never leaves your device.
Choose a file to see its details here. Nothing is uploaded: everything runs in your browser.
How to use the obj to stl converter
- 1Choose your OBJ fileDrag it onto the panel or click to browse. It's read locally and never uploaded.
- 2Check the previewOrbit the model and check the triangle count, size and materials before converting.
- 3Download the STLExport a STL with one click. Downloads are included with every plan.
What carries over
- The STL is written Z-up, which is what slicers and scan tools expect.
- Units: OBJ is unitless and STL is unitless (slicers assume millimetres). Numbers are copied 1:1, so check the size in the target app.
OBJ vs STL
| OBJ | STL | |
|---|---|---|
| Full name | Wavefront OBJ | stereolithography mesh |
| Appearance | basic materials in a separate .mtl file | no colour or materials |
| Animation | No | No |
| Units | unitless | unitless (slicers assume millimetres) |
| Best for | older 3D software and CAD-adjacent tools | 3D printing slicers |
Questions
- Is my OBJ file uploaded?
- No. The OBJ is parsed and the STL is written by JavaScript in your browser tab. The file never reaches our servers.
- Will the STL look the same as the OBJ?
- The geometry is identical. STL holds no colour or materials, so surface appearance changes. See the notes above for this exact pair.
- Is there a file size limit?
- Files up to 150 MB open, but very large models depend on your device's memory. Desktop browsers handle big files best.