Helper processes

Chrome gives web pages and extensions their own processes so they are kept apart from each other. More open tabs, sites and extensions usually means more helpers. Other browsers and many desktop apps built on web technology work the same way.

Activity Monitor names the helper but not the page it is running. Browsers have their own task managers for this. In Chrome, open Window, then Task Manager, to see each tab and extension with its memory and CPU.

Close the heavy tabs or turn off extensions you do not use. Quitting a single helper in Activity Monitor usually just makes that tab or extension crash, so it is better to close it from inside the app.

Add up the rows for the app and its helpers. In Activity Monitor, View, All Processes, Hierarchically shows processes under their parent, which can help, though some helpers are started by other system processes and will not appear under the app.

Most helpers carry their app's name, but not all do. Activity Monitor and Terminal can both tell you where a helper comes from.

1. In Activity Monitor, double-click the helper, or select it and click the Info button in the toolbar.
2. Read the Parent Process field. For a browser helper it is usually the browser itself.
3. For the full picture, find the helper's PID in the PID column and run ps -o ppid=,comm= -p <PID> in Terminal. It prints the parent's PID and the helper's full path, and the .app name in that path is the app that shipped it.
4. To see every row for one app at once, type the app's name in Activity Monitor's search field. The list filters down to the app and all of its helpers that share its name.

Browsers based on Chromium, and many desktop apps built with web technology, split work into helpers with a label in parentheses. Chrome's helpers, for example, include these:

• Helper (Renderer): runs web pages and web content. Usually the busiest and the most numerous.
• Helper (GPU): does drawing and video work on the graphics processor for the whole app.
• Helper (Plugin): runs plug-in code. Some apps, such as Slack, include this one.
• Helper with no label: a utility process, for tasks such as networking, audio, or storage.

Many helpers on their own are normal. The count mostly tracks how many tabs, windows, sites and extensions you have open, and each one uses little when idle.

It becomes a problem when a single helper stays near the top of the % CPU list while you are not using the app, or when the app's helpers together use so much memory that Memory Pressure turns yellow or red. In both cases, open the app's own task manager if it has one, find the page or extension responsible, and close it from inside the app.

Extensions deserve a look even when you are not using them. In Chromium browsers, extensions run in helper processes of their own, so an extension you installed and forgot about can hold memory and wake up the CPU in the background. Remove the ones you no longer need.