Sleepy Tabs

This extension helps you preserve your precious memory:
- sends inactive tabs to sleep automatically after a set number of minutes (can be changed through the options).
- optionally keeps inactive tabs awake based on an exclude list of domains set in the options.
- discarded tabs wake up and reload as soon as they're opened.

You can now keeps all your favorite tabs opened without worrying about RAM consumption, and still get to receive notifications from your preferred webapps thanks to the exclude list.