Converting .OBJ files to .STL files

I have a beautiful prototype for a Drone Safety Device, except it is in .OBJ. Can anyone help me to get this to a .STL file so I can get the thing built?
2 Answers

You can do OBJ to STL with CAD Exchanger, for instance using desktop GUI or CAD Exchanger Cloud (https://cloud.cadexchanger.com). The latter is fully in a browser, not installation required, and has a free plan.
Other formats are also supported.
ROFL!
Many programs can do it... Upload OBJ here
Free converter - http://meshlab.sourceforge.net/
Easy for you. I'm not an engineer. Thanks! Inspire for the tip.