Because the majority of today's web browsing takes place within dynamic web apps, they all require CPU to load fresh data on a regular basis.

You don't have any available RAM. Even though open tabs eat into your available RAM, you also have to consider all the other active processes that could cause your Mac to start throttling apps.

Even though open tabs consume RAM, you must also consider all of the other ongoing activities that could cause your Mac to throttle programmes.

One or more of your Safari extensions isn't working properly. Extensions are the weakest link in the chain when it comes to security and stability. Make sure you only use the ones you trust and minimize their use in general.

Make sure you only utilise the ones you trust and that you use them sparingly.

You haven't updated your macOS to the most recent version. Safari updates are available through macOS updates, and it's always a good idea to keep up with them.

Safari updates are usually included with new macOS releases. However, Apple does occasionally release standalone Safari security patches and additional features via the same Software Update menu.

To get the most recent version of Safari, go to: