OBJ to STL Converter
Processing entirely on your device — large files may take a moment.
OBJ is the veteran plain-text 3D format from Wavefront: vertices, faces and texture coordinates in a human-readable file that almost every 3D package imports. STL is what 3D printers and slicing software (Cura, PrusaSlicer) expect — the final step before printing.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How to convert OBJ to STL
- 1
Select your files
Drag & drop your OBJ files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to STL". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted STL file individually, or grab everything at once as a ZIP archive.
Frequently asked questions
Is this OBJ to STL converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
What happens to colors and materials?
The STL format only stores geometry, so colors, textures and materials from the source file are dropped — the shape converts perfectly, appearance does not. If you need materials, convert to GLB instead.