Safari CPU Usage at about 100%

[seme332]

Since I updated to macOS 10.13.5 my Safari CPU usage always jumps to roughly 100%, freezing Safari and spinning up the fans. Anybody experiencing similar issues? I have tried deactivating all extensions with no luck.

 

[kohlson]

Have you tried starting Safari without previous tabs (Shift+Click on Safari app). It could be one of the tabs that is "running away."

 

[Fishrrman]

I've had Safari up-and-running for 5+ hours today, logged onto [mostly] Macrumors.

I just opened Activity Monitor and it shows Safari using 0.2% of CPU.
Makes me wonder what other people do to get it to jump to 100% or more?

OP:
How many tabs do you keep open?
I -NEVER- use tabbed browsing, EVER. Not one tab, ever.
I ALWAYS open pages using the "open in new window" command, and close those pages I don't really need to keep open.

I've devised a way to completely "clean out" Safari, which I do at regular intervals (at least once each day):
Here's what I do (this works for Low Sierra and El Cap, not sure about High Sierra):
1. In Safari, go to the Develop menu and choose "empty caches" -- does just what it says.
1. Open the folder "home/library/safari"
2. Type "command-A" to select all items within
3. Hold down the command key and click "Extensions" and "Bookmarks.plist" to DESELECT them.
4. Type "command-delete" to move EVERYTHING ELSE in that folder to the trash
5. Empty the trash.

Now, when I re-open Safari, it starts -almost- "completely clean", with few traces of anything that was there before.
Bookmarks are retained.
Passwords are retained.
Extensions are retained.

I also use a "cookie manager" to DESTROY ALL COOKIES with the exception of those I wish to retain every time Safari closes.

Doing all of the above keeps Safari running lean and clean for me...

 

[seme332]

OP:
How many tabs do you keep open?
I -NEVER- use tabbed browsing, EVER. Not one tab, ever.
I ALWAYS open pages using the "open in new window" command, and close those pages I don't really need to keep open.

I usually have about 3-4 pinned Tabs and 4-6 normal Tabs, but lately with this issue I only open Safari with maybe 1-2 Tabs open, doesn't matter what Website.

I also followed all the steps you described, (THANK YOU for those), with no luck Every time I open Safari again (start the App) the CPU usage goes up to over 100% and Safari freezes for a while, then it will calm down but go back up again after just a little while. It's really strange.
[doublepost=1530607269][/doublepost]Just two screenshots...

1. Safari right after opening it (closed everything Safari-related in Activity Monitor before):
https://pasteboard.co/HsIEqOK.png

2. Safari after two minutes, calming down:
https://pasteboard.co/HsIEJLk.png

 

[kohlson]

Safari freezes for a while

Fisherman had good advice. I'm not sure if this is covered by his tips, but have you tried cleaning out cookies? I don't normally do this but a few years ago I had accumulated so may that it took 10 minutes to compete. And my browser went back to working as it should.
Safari Preferences-Privacy-Manage Website Data.

 

[seme332]

Fisherman had good advice. I'm not sure if this is covered by his tips, but have you tried cleaning out cookies?

Just tried it, still seeing the same CPU spike when launching Safari and after it being open for a while :/

 

[cobracnvt]

Just tried it, still seeing the same CPU spike when launching Safari and after it being open for a while :/

Maybe there is an issue with one of your pinned tabs.

 

[kohlson]

If you've tried a safe mode start, and cleared cache and cookies, try deleting the plist. Perhaps Reinstalling Safari. Also, try EtreCheck, and see if it finds anything.