Safari lagging

I am having the exact same issue. When I look at the Activity Monitor I see "spindump" a ton when running Safari. When I run Firefox I have no lag and no spindump. The strange thing is that I see openvpn-service and airportd at the top of my CPU run queue nearly all the time. I turned off airport networking and removed it from "network" in system preferences so I only support a wired connection. I have no explaiation for this or the openvpn-service as I have turned off any VPN software. The CPU usage is not horrible for the openvpn and airportd things but the spindump thing with Safari makes it unusable.

I have a strange issue with my MacBook Pro. This problem seems to have started before the Beta. But when using Safari the screen will sometimes flicker. Has anyone else experienced this issue with a mid-2015 15" retina?

i got the same isue, safari report me many errors and restart by it self 😟 hope apple update this beta soon.

Yup. Safari is lagging for me after clicking nearly every link or tab. I get the Spinning Beach Ball of Death.

Running macOS Sierra v10.12 Beta (16A201w) on my MacBook Air (13-inch, Mid 2013)

same to me, need new beta release

I want to echo that this seemed to help in my specific instance. I had only done an upgrade from 10.11.5 to 10.12, and even though Safari preferences did not indicate any installed plugins or extension, they still remained in the Library folder. Deleting them immediately fixed removed the lag-time between clicking a link and and the browser starting to load. Thanks!

Totally agree. Just deleted everything from Internet Plug-ins folder - now Safari responses almost instantly. Now I can only see a problem of incompatibility of some apps, but that's totally fine - It's a developer preview.

Just had Safari become unresponsive but quit Safari & re-open fixed for me. Uptime on this iMac almost two days with Safari always open apart from iMac sleep.

I noticed it in Chrome as well. Switching to Safari made things better.

The only thing I've found to work is to create a whole new user account!

But now it seems that Safari doesn't work for me when I connect to my VPN, only Chrome does. Haven't tried Firefox.

I experienced the same thing early this week and switched to Firefox, which was a painful choice. Then, while on another wifi network, I fired up Safari and am getting perfect performance. I don't know if there's a cache or network setting or difference in the networks, etc. but don't lose hope.

Same here. Some web sites have problems, one example is the Logitech website and hit for any product the support tab.

If you upgraded to Sierra from previous OS X installs, clear these directories:

~/Library/Internet Plug-ins/

/Library/Internet Plug-ins/

That fixed the issues for me.

I don't have anything to contribute other than on my test Mid 2014 MBP with 1Password, AdBlock Plus, WOT, and ClockToPlugin ( no longer needed really) I haven't see any issues with speed at all. It also works fine over VPN (VyprVPN - using OpenVPN). I don't see any abnormal log entries either.

I also can say that all of the lagginess and weird beachballs went away after I deleted all of the plugins. Now it just reacts as a normal browser should.