What is com.apple.WebKit.WebContent?
Safari runs each website in its own com.apple.WebKit.WebContent process, which keeps one bad page from crashing the others. Other apps that show web content, like Mail or apps built with web views, use the same kind of process.
In recent macOS versions, Activity Monitor often lists these processes by the website's address, which makes the busy tab easy to spot.
Why is com.apple.WebKit.WebContent using so much CPU?
- A heavy page: video, animated ads, web apps, games or a page stuck in a loop.
- Many tabs left open, some of which keep running scripts in the background.
- Extensions that run on every page.
How to fix high com.apple.WebKit.WebContent CPU usage
- Confirm it in Activity Monitor. Press ⌘ Space, type Activity Monitor, open the CPU tab and sort by % CPU. Watch
com.apple.WebKit.WebContentfor a minute: short spikes are normal, only steady high usage needs fixing. - Find the tab. In Activity Monitor, look at the process name or address next to the high CPU number and close that tab.
- Close tabs you aren't using, especially video and web apps.
- Turn off extensions one at a time in Safari › Settings › Extensions to find a heavy one.
- Update Safari and macOS, which improve performance and fix bugs.
More help: How to check CPU usage on a Mac