Although I've not yet updated Safari 11.1.2, I'm getting an 'alert' along the top of its window stating:
"This webpage is using significant memory. Closing it may improve the responsiveness of your Mac."
Activity Monitor does show Safari as the top memory user not counting kernel_task and WindowServer. And the particular (WebMD) url shows between those two items, followed by Safari, itself. AM shows Safari as the number one item in "Energy Impact", ocassionally swaping places with AM. I've not used AM much, but there are disclosure arrows by almost every app. Clicking those then displays (in Safari) urls, plugins, daemons, etc. and their specific "impact". Once again, the top user is the particular url.
I disabled both AdBlock Plus and uBlock Origin to see if that made any difference:
After 5 minutes with AdBlock Plus only disabled: No change.
Enabled AB+ and dsabled uBlock Origin, waiting 5 minutes: No change.
Only thing that cleared the 'problem' was closing the page... just as the message suggested. I can't remember ever seeing that message before. I've been using that version of Safari for a few weeks, I think. I don't often visit that site nor do I know if the recent installation of uBlock Origin is part of the cause. Just interesting...
