How Chrome Extensions Affect Browser Performance and Battery Life

Most extensions cost little, but a few can slow every page you open or keep your laptop busy in the background. Chrome shows you exactly which ones are using resources, so you don't have to guess.

Where the cost comes from

• Code that runs on every page. Extensions that change pages, such as ad blockers, dark mode, grammar checkers and translators, inject scripts into each site you visit. A heavy script slows page loads a little on every site.
• Background work. Under Manifest V3, an extension's background code sleeps when idle and wakes for events. Extensions that sync, check for updates or poll often wake up more, which costs battery.
• Memory. Each extension uses some memory. Ten small ones rarely matter; one leaky one can.
• Network activity. Extensions that fetch data, such as price trackers or coupon finders, send requests as you browse.

Some extensions save resources: ad and tracker blockers often make pages load faster because they stop heavy ad scripts from loading at all.

Find the expensive ones

1. Press Shift + Esc on Windows, or open the menu → More tools → Task manager.
2. Look for rows starting with "Extension:". Sort by Memory or CPU.
3. Watch for extensions using CPU while you're not doing anything. That's the battery drain.

To confirm, turn off all extensions, then turn them back on one at a time. See how to disable extensions without uninstalling them.

Keep Chrome fast and easy on the battery

• Remove what you don't use. The easiest gain.
• Limit site access. At chrome://extensions, open an extension's Details and set Site access to "On click" or specific sites. It then can't run on every page.
• Turn on Memory Saver and Energy Saver in Settings → Performance. Memory Saver frees memory from inactive tabs; Energy Saver limits background activity on battery.
• Close tabs, or let them sleep. Open tabs usually cost more than extensions. Patrick Bushe's Tab Manager puts idle tabs to sleep automatically.

Extensions that work in the background on purpose

Some extensions are meant to do work while you browse. Ghost Browser, for example, visits random sites in the background to blur your ad profile, which uses some network and CPU. It has an intensity setting and an only-when-idle mode so it stays out of your way. Know which of your extensions work this way, and set them to match your battery and data plan.