Whether you are a developer or if you like to test any previous or beta version before it is finally released as stable to the public, perhaps this way of knowing that process identifier uses each tab or window It can be useful at all times when you have to stop it if it causes you some kind of problem.
For this, Safari on Mac has a small hidden menu that makes this task much easier to carry outThis debug menu, apart from many other "advanced" options, brings one that allows you to identify, as I have already mentioned, each process ID in the window that we find in addition to the title.
This optional configuration is primarily intended for users and developers who need to quickly see the PID of a concrete web page directly from the window's address bar. In other types of situations, it may be additional information not required and therefore certainly useless, so it is more advisable to do it through the activity monitor.
To show the Debug "hidden" menu in the title bar, we will only have to enter the system terminal and enter the following through the command line:
defaults write com.apple.Safari IncludeInternalDebugMenu 1
Once this is done we will have to restart browser to show us the Debug menu definitively, after that we just have to click on it and move to «Miscellaneous Flags» and later click on the last option available «Show Web Process IDs in page web titles»
From this moment on, it will no longer be necessary to enter the activity monitor, identify the process and close it, but it will be enough to have the terminal open and with the Kill command followed by the PID, we can end that specific process that is giving us problems.