This webpage is using significant energy on this website!

I get this on a regular basis myself. Sometimes It is obvious why - pages with lots of ads (especially animated ads) tend to do this quickly, even if the only tab or window open.

But I still believe there is an issue in Safari - as it would seem that sometimes this message comes up on rather mundane web pages - And yes, over time, those pages slow/bog down.

When the "solution" is to use a different browser - that doesn't speak very highly of Apple's Safari browser.

It's just a message. If you prefer not to know that a webpage is using significant energy you can choose to ignore it or use a different browser. It may use even more energy and slow down your Mac leaving you to wonder why.

If you have questions try perusing the "Similar questions" linked above, which are likely to reveal similar answers.

This is observably false.

Just in the time since I posted the above, I have had windows open that showed the warning... then after several minutes reloaded on their own.

I've also observed web pages having this pop up, then begin to become unresponsive -

There is more to the story than "just a message", as I can open the same page with several other browsers and never have it slow down, nor does it "bog down" my MacBook Pro. It is specific to Safari.

You should not need to force Safari to quit.

If you notice your Mac is becoming overly burdened by that web page's content, just close the web page.

If you would like further assistance please contact Apple Support, here: Contact - Official Apple Support. I am no longer interested participating in this Discussion.

Good luck!

Ignore it then. Your choice. No one is forcing you to read it.

Ignore what? The message (that often is followed with computer slowdowns or reloaded web pages?