Hi @Oli, it’s generally not a great idea to be closing and re-creating the win Window instance that Builder initialises. That could break all sorts of things (for example, maybe its list of auto-drawing stimuli). You’ve already noted that all of the existing visual stimuli would need to be linked back to the new window instance, and that could easily go wrong. The main PsychoPy window instance doesn’t need to be destroyed: it can simply be minimised, and then you could open the web browser as above. The PsychoPy window could then be maximised and reactivated again, as per this thread:
Having said that though, I’m not sure how PsychoPy would know when to do the maximisation step (i.e. how it would learn when the web browser window has finished/been closed).