This is a pure-browser tool that requires no sign-up. You upload a DWG (or DXF), set the pattern scale and rotation, and it returns a PAT file.
Artificial intelligence is entering this space. New online converters are emerging that use machine learning to identify repeating units in large DWG files automatically. Instead of you drawing a bounding box, the AI detects the natural tile size. Additionally, WebAssembly (WASM) allows converters to run complex CAD parsing directly in your browser, meaning your DWG file never leaves your computer—solving the security issue entirely. dwg to pat file converter online