Browsers using significant energy

An energy impact reading of ~1000 across multiple browsers (Safari, Chrome, and now Edge) strongly suggests the issue isn't actually a bug inherent to any single browser. Instead, the browser is likely reacting to a system-level process, a rogue web tab, a corrupted extension, or hardware acceleration loops triggered or amplified since updating your macOS.

Here is a step-by-step troubleshooting guide to track down the root cause and get that energy meter back to normal:

1. Isolate the Culprit via the Browser's Internal Task Manager

Browsers run dozens of hidden helper processes (extensions, tabs, ads, background scripts). Activity Monitor only shows the parent app, which hides what inside the browser is acting up.

• In Chrome / Edge: Press Shift + Esc while the browser is open to pull up its internal Task Manager. Look at the Energy Impact or CPU column to see which specific tab, extension, or plugin is spiking the meter.
• In Safari: Go to Window > Activity Monitor (or press Option + Command + \) inside Safari to see per-tab energy usage. Often, a single looping ad, a poorly coded crypto-script, or a heavy web app (like Google Docs, Slack, or YouTube) will lock onto a thread and cause massive power draw.

2. Check for Rogue Browser Extensions

An outdated or incompatible extension trying to sync or run scripts in the background can thrash your CPU across anyChromium or WebKit browser.

• Temporarily disable all extensions in your active browser.
• Restart the browser and check Activity Monitor. If the energy impact drops, re-enable your extensions one by one to find the culprit. Ad-blockers and password managers are common offenders if they get stuck in an update loop.

3. Check for Hardware Acceleration & Video Decoding Glitches

Modern web pages rely heavily on your Mac’s GPU for rendering animations and video. Sometimes, macOS updates break hardware acceleration hooks, forcing your CPU to do heavy lifting.

• In Chrome or Edge, go to Settings > System and performance, and toggle "Use graphics acceleration when available" to the opposite setting (if it's on, turn it off; if it's off, turn it on), then relaunch.

4. Investigate System-Wide Culprits (The macOS Factor)

Since this started right after a macOS update, it can sometimes be tied to background indexing or GPU window-server loops.

• Spotlight Indexing: Major updates often trigger a background re-index of your hard drive (mds or mdworkerprocesses). If Spotlight is indexing while you have a browser open, the combined thermal and resource load can make browsers look like the primary victim. Open Activity Monitor, sort by CPU, and check if mds is running hot.
• Safe Mode Test: Shut down your Mac, then press and hold the power button until you see "Loading startup options." Hold the Shift key and click Continue in Safe Mode. Open a browser there. Safe mode clears system caches and stops third-party background daemons. If the browser behaves normally in Safe Mode, a background login item or driver is conflicting with your browsers.

5. Reset Browser Plist / Preferences

If configuration files have corrupted during the macOS system upgrade:

• For Safari: Close Safari, go to Finder, press Command + Shift + G, and paste: ~/Library/Preferences/. Look for com.apple.Safari.plist, move it to the desktop (so it resets to default), and reopen Safari.