Annoyed by frequent "This website is using significant energy" alerts in Safari? Turn them off!

[SpecMode]

I finally got irritated enough by those alert pop-ups on the top of every other Safari tab that I started digging for a way to turn them off once and for all, without disabling useful functionality (e.g. extensions) in the process. It turns out that there is a Safari debug setting that can be enabled to suppress these alerts; here are two methods that can be used to turn this setting on.

Method 1: Enable the Safari debug menu, using the instructions provided here. Note that whatever app you use to modify the Safari preferences file must first be granted either write access to the Preferences folder or Full Disk Access in System Preferences -> Security -> Privacy. Once you've enabled the debug menu, launch Safari, and enable the setting Debug -> Suppress Alerts.

Method 2: Ensure that Terminal is listed and enabled for Full Disk Access in System Preferences -> Security -> Privacy -> Full Disk Access. Launch Terminal, and run the following command:

defaults write com.apple.Safari DebugSuppressAlerts 1

To re-enable alerts, use this command:

defaults write com.apple.Safari DebugSuppressAlerts 0

Hope someone finds this useful!

ADDENDUM: It looks like this may only suppress very specific types of alerts, and the one for "This website is using significant memory" may not be one of them. 😕 I'm gonna keep looking for an alternative method of disabling these messages, and if I find it, I will post it here.

 

[chscag]

Good info. Thanks.

 

[BrianBaughn]

What alerts other than the one about significant energy would be silenced by this method?

 

[zorinlynx]

It's good to have this feature! I wonder if it also suppresses the "tab is using significant memory" alert which I've dealt with in the past when using Twitter.

Oddly enough I've not seen that alert since I upgraded to Big Sur, so I'm guessing whatever problem was leading to that alert was fixed or got better. But if I see it again I'll definitely try this! Thanks for posting.

 

[Solenoid289]

Great tip. Thank you.
But "Using significant memory" alert is still persists.
As @zorinlynx mentioned, it's better in Big Sur + Safari 14, but watching 4K videos in YouTube, sometimes memory alert pops up.

 

[Unsupported]

What alerts other than the one about significant energy would be silenced by this method?

Good question, I hope we get an answer.

I've seen it frequently on Facebook and it goes away if I reload the page. I've followed SpecMode 's instructions so hopefully I won't see it again, but I would like to know what else it may be suppressing.

 

[SpecMode]

What alerts other than the one about significant energy would be silenced by this method?

I wish I had an answer for that, if I'm honest. This setting seems to be entirely undocumented, as far as I can tell, and it doesn't even suppress all alerts; if the web process crashes for a given tab, the "This webpage was reloaded because a problem occurred" message will still pop up at the top of the window.

FWIW, I have only tested this on Safari 14 in Big Sur, and while I have not yet been able to trigger any alerts other than the one described above, it's entirely possible that it doesn't behave identically on Catalina (or earlier) or even prevent all alerts in Big Sur.

 

[Unsupported]

I've seen it frequently on Facebook and it goes away if I reload the page. I've followed SpecMode 's instructions so hopefully I won't see it again, but I would like to know what else it may be suppressing.

Update: It doesn't work for me 😞

 

[SpecMode]

Added an addendum to the original post with caveats. I'll note that I still haven't been able to get any of these messages to pop up since turning on this setting, but I'm willing to concede that it may indeed just be dumb luck that it hasn't happened to me yet.