WebThumbnailExtension Web Content High CPU/Memory Usage

I've been running into this issue. Initially, I thought it was because my MBP M3 Max was connected to the Microsoft Redmond domain and that Intune MDM policies were buggy. I'm not sure QuickLook is the culprit (rather, I'm looking at you Excel and PowerPoint, or Teams 😏). Anyway, for awhile, whenever my CPU starts hitting 100% and computer starts becoming sluggish, I was using Activity Monitor to force quit all those pesky WebThumbnailExtension Web Content instances.

You can also use Automator to make an "app" that will programmatically kill those instances on demand. Here's the Run Shell Script I use:

#!/bin/bash

# Search for the processes and extract their PIDs
PIDS=$(ps -axo pid,command | grep -i "System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent" | grep -v grep | awk '{print $1}')

# Check if any PIDs were found
if [ -n "$PIDS" ]; then
    echo "Killing the following processes:"
    echo "$PIDS"
    echo "$PIDS" | xargs kill -9
    echo "Processes terminated."
else
    echo "No matching processes found."
fi

Hope this helps!