About ConvertSTL

Mesh formats (STL, OBJ, 3MF, PLY, GLB, FBX and the rest) are parsed and written with three.js. STEP and IGES are read by OpenCascade, the same CAD kernel FreeCAD is built on, compiled to WebAssembly and shipped to your browser.

Your file is opened by JavaScript inside the page. It is never uploaded, never queued on a server and never written to disk anywhere but your own downloads folder. Once a page has finished loading you can disconnect from the internet and the conversion still works.

Most online converters upload your file to a server, cap the file size, stamp a watermark on the result or ask you to create an account first. None of that is necessary: a modern browser is fast enough to do the work locally.

Engineering files are also often confidential. A supplier drawing or an unreleased product part should not be sitting in a stranger's storage bucket because someone needed to change a file extension.

Nothing. There are no accounts, no daily quotas, no watermarks and no ads on the tools. Because the conversion runs on your machine there is no server bill to recover.

Found a file that will not convert, or a format you need? Send it over and it will get looked at. support@convertstl.com