🌿 Web CPU Tamer
Reduce your browser’s energy usage and CPU load by adding smart, invisible delays to script execution.
📌 What does this userscript do?
Web CPU Tamer introduces a lightweight, intelligent delay into the browser's task scheduling system. By doing so, it prevents web pages from overwhelming your CPU with tightly packed timers and animations — all without breaking any functionality.
This leads to:
- Lower energy usage 🔋
- Reduced fan noise 🌀
- Smoother multitasking 🧠
- A cooler and more efficient browsing experience 🌡️
💡 How does it work?
This script replaces the browser’s built-in scheduling functions with optimized versions:
| Original |
What it does |
setTimeout / setInterval |
Adds two micro-delays before each execution using queueMicrotask and MutationObserver. This lets the browser handle layout and paint cycles more gracefully. |
requestAnimationFrame |
Adds a subtle delay by measuring the time difference across animation frames and yielding execution until the browser is ready. |
clearTimeout / clearInterval / cancelAnimationFrame |
Fully respected and properly tracked, so cancelling still works perfectly. |
Under the hood, these replacements insert a two-stage implicit delay around scheduled tasks — just enough for the browser to breathe without making apps feel sluggish.
✅ Key Features
- ⚡ Reduces unnecessary CPU usage
- 🔋 Improves battery life
- 💻 Optimizes responsiveness during heavy workloads
- 🧠 Smart async delay mechanism with DOM-based triggers
- ⛔ Fully respects cancellation (no memory leaks!)
- 🧩 Compatible with all websites — no modifications to content
- 🧪 Special handling for performance-sensitive sites like YouTube + Brave
🚫 What it doesn't do
- ❌ It doesn’t block content, ads, or trackers
- ❌ It doesn’t interfere with page visuals or features
- ❌ It doesn’t slow down websites unnecessarily
- ✅ It only intercepts background scripting in a subtle way
🖼️ Where does it run?
This script runs on all http:// and https:// pages, except direct links to file types like images or logs:
.txt, .png, .jpg, .jpeg, .gif, .xml, .svg, .manifest, .log, .ini
That means no interference with direct downloads, image views, or text-only pages.
🧪 Browser Compatibility
| Browser |
Status |
| Chrome / Chromium |
✅ Full support |
| Firefox |
✅ Full support |
| Edge |
✅ Full support |
| Brave |
✅ Special handling for YouTube |
| Safari |
⚠️ Mostly works, limited mutation timing accuracy |
Also works with:
- ✅ Tampermonkey
- ✅ Violentmonkey
- ✅ Greasemonkey (v4+)
🔐 Security & Safety
- 🧠 No external libraries
- 🕵️ No trackers or network requests
- 🚫 Doesn’t collect or share data
- 📦 MIT Licensed — open and inspectable
🧙 Author
CY Fung
🔗 GitHub Support Page
🧾 License
MIT License
You are free to use, modify, and redistribute.
