Caffeine – Keep Awake

This extension keeps your operating system from going into hibernate or sleep mode. There are two levels of operation:
1. "Display": prevents single or multiple monitors from dimming or displaying screensavers
2. "System": prevents the entire system from going into the power-saving state

Features:
1. Operates on display or system level
2. Keep the system awake for a specified period (from 5 minutes to 24 hours) and allow the system to sleep afterward.
3. Keep the system awake while downloading a file. Use it to download a large file without being interrupted when you are not present. The system will go to the idle state when the job is over.

The extension only offers a toolbar button that is inactive by default. You can click the button once to active the keep awake state and prevent from sleeping. Another click will release this state back to the default. To change the level, use the right-click context menu items. This extension does not alter the computer's power settings (PC, Mac, or ChromeOS) when it is disabled. However, if enabled, the extension overrides these settings and prevents it from going to sleep mode.

Will this extension prevent my computer from suspending when its lid is closed?
Some operating systems permit background activities even if the lid is closed. Some others do not allow it. If you have an old Chromebook, the operating system suspends all activities when the lid is closed.

Some use cases:
1. You have an ongoing download, and you don't want the network connections to break
2. During a presentation, it might happen that you don't touch the mousepad for a while, but you need to use your screen actively.
3. You are reading an e-book or PDF, and you don't want the screen to dim
4. You want to temporarily keep the computer awake without altering the power settings of your OS.