There was a post about this a few years ago now and it was said there was no functionality to change the size of the pop up window in Arc Online. I am wondering if that functionality has been added?
Hi @edward33
I don't think this is added just get as the idea is still open: Auto-size/Customize width of ArcGIS.com map popups - Esri Community
Just can follow the idea there as well can vote for it.
Thanks, will do!