Safari is slow after Mojave update

Safari/Preferences/Advanced - enable the Develop menu, then go there and Empty Caches. Quit/reopen Safari and test. Then try Safari/History/Show History and delete all history items. Quit/reopen Safari and test. You can also try try Safari/Clear History…. The down side is it clears all cookies. Doing this may cause some sites to no longer recognize your computer as one that has visited the web site. Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J. When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder. Select Library/Caches/com.apple.Safari/Cache.db and move it to the trash.

Go to Safari Preferences/Extensions and turn all extensions off. Test. If okay, turn the extensions on one by one until you figure out what extension is causing the problem.

Safari Corruption See post by Linc Davis

If that doesn't work, try running this program in your normal user account , then copy and paste the output in a reply. The program was created by etresoft, a frequent contributor. Please use copy and paste as screen shots can be hard to read. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy Report” and then paste into a reply. This will show what is running on your computer. No personal information is shown.

Etrecheck – System Information

As somebody else before me said, removing the cooking and browser history didn't really help me. However, removing AdBlocker from my computer did. Now Safari works just fine but I don't have an ad blocker and I will have to look for a new one.

Me too, ABP was the problem of the lagging Safari. I tried several others like Adguard but settled in with 1Blocker (v 1.4.3) which works wonderful and integrates with Safari content blocker api. (This is a benefit since older adblockers are able to see all the content on the sites you visit.)

This may not be strictly relevant to the OP, but for others who say that sites containing a lot of graphics are slow (like iCloud with its cursor-tracking dynamic background): there appears to be some issue with Safari on Mojave not engaging high-performance graphics. Trying to draw complex stuff without using the GPU gets us this chunky 1990s-feeling performance and seems to back up the main thread so the whole computer bogs down.

For a battery-eating workaround you can turn off automatic graphics switching:
iCloud suddenly roars back to life - this de-***** the iCloud home page in real time - but you may lose battery performance if you have to leave this setting this way. Toggle it back off to return to late-nineties mode.

There were changes in Mojave to enable the use of external GPUs, and it's likely Safari didn't track them properly and now can't demand GPU on its own when it needs it.

If you have Ad Blocker enabled in Safari, try turning that off. Recently Apple deprecated an API that is frequently used by Ad Blockers and it looks like the new replacement API is not as fast as the old one (no proof, just a speculation).

Having used Mojave for about three months now, I feel I can provide a good update as to what are the issues at hand and what can be solved:

-Everything is slow: disable ad-blocker, and any other extensions (like Honey, which made Amazon unusable)

-Specific websites are slow: try disabling extensions, but sometimes doesn't help. (Thesaurus.com is nearly unusable)

-The notes app is delayed when typing by one second, two seconds, three seconds......unfortunately a major flaw, supposedly (from what an Apple Genius associate told me) caused by significantly more frequent iCloud updating (like on a per-character basis, versus waiting a few seconds)

Final remarks:

-Mojave is beautiful, advanced, intricate

-Mojave is well polished, at the very least design-wise, if not glitch-wise

-Mojave is NOT OPTIMIZED for certain executions (like extensions, notes, websites) which is a major flaw and a massive deterrent to use of the otherwise highly applaudable operating system.

Do you use Adblockplus? For me choosing another ad blocking software was the solution.

I had the same problem. After deinstalling my Adblocker (ABP from Adblock Plus), Safari works fine again.

Greets,

Wolfgang

I also had the same problem and after removing Adblocker (ABP from Adblock Plus), Safari starts working fine.
Thanks for help)

seems that the problem is adblocker! i uninstalled it and now Safari works fine!

I was having a similar problem--I could be, say, in my amazon cart and nothing, no clicks or mouse movement would register for at least an extra 5 or 10 seconds. youtube, forget about it. And google docs just froze instantly.

I turned off all my extensions: ad blocker and honey, I think it worked but I need more time to confirm 100%.

MPB 2016 15" i7 16GB RAM. Mojave.

yep, it was adblocker that caused the slow loading time for my mac after disable it was normal again.... anyone know any good adblocker extension ?

Problem solved at macOS Mojave 10.14.1 (18B75)

Thanks for this. Had the same issue and uninstalling ADB worked like a charm.