Its a hosted tool and everything runs in the browser. It would be interesting to compare results because it could be that c++ is better suited for these kinds of operations.

For me this begs the question, why does this question always come up in selfhosted communities? ;)

For me I like self-hosted apps because I switch between desktop and laptop, and some tools are nice to have on a phone too. This way I pull it in-house, and can use it everywhere. Besides that, there are two other laptops in the house and if I am using those I have the same tools available as well. It its something I need to help the kids with, and they need to use it more often they too can use it regardless of device. Plus its one less thing to install when setting up a new device.