Since most of our web browsing today happens inside dynamic web apps, all of them need to use CPU to constantly load new information.

You have too many CPU-intensive tabs open.

While Safari on its own doesn’t use much resources and is very reliable, it might crush due to overloading your RAM or CPU for a few reasons: If you do tend to get the “Safari quit unexpectedly” messages more often than you’d like to and are wondering “Why does Safari keep crashing on my Mac?” - keep reading to find out about all the Safari freezing fixes you need. In fact, an unresponsive Safari can freeze your whole Mac as well. Most notably, it’s not uncommon for Safari to freeze, show a spinning beach ball, stop responding, and crash when performing under load. However, just like most browsers (or any other apps, for that matter), Safari has its share of troubles. It’s generally considered to be a fast and stable browser due to its tight integration with the macOS, and has been updated continuously with new features and security patches since its initial release in 2003.

As the default browser on Mac, Safari is used by hundreds of millions of people every day.

Mail on imac keeps freezing