Right now, as you read this sentence...
Your browser is burning energy
and no one will tell you how much.
Every click. Every scroll. Every page load.
Energy flows from power plants, through cables, into data centers, across fiber optic lines, through your router, into your device—
Just so you can see these words.
The internet consumes more electricity than
But here's what no one talks about:
You can't know.
Because browsers won't tell you.
The Invisible Wall
Your computer knows exactly how much power it's using. Your operating system can measure it precisely.
But the browser? It's locked away. Sandboxed. Silent.
This isn't a bug. It's a feature.
Security researchers discovered something terrifying:
By watching power fluctuations, attackers could extract encryption keys. Your power consumption was leaking your secrets.
Advertisers found a new way to track you:
Your battery's unique drain pattern became a fingerprint. They could identify you without cookies.
So browsers did the responsible thing:
They locked it all down. Removed the Battery API. Blocked all hardware access. Problem solved.
Except now, no one can measure web energy.
And what you can't measure, you can't improve.
So we asked ourselves:
What if we could measure it anyway?
We can't measure power directly.
But we can measure everything else.
And here's the key insight:
and then run it in your browser...
we can learn your device's energy signature.
Introducing: Energy Estimation
It doesn't need to be.
You don't need millijoule precision to know that a 500 mJ page is ten times worse than a 50 mJ page.
You just need to see the difference.
What becomes possible
See which sites drain your battery. Discover the hidden cost of your daily browsing. Make choices that matter.
Get real-time feedback on energy impact. Optimize for efficiency, not just speed. Build websites that respect resources.
If every website reduced energy by 20%, we'd save 80 TWh annually— equivalent to 56 million tons of CO₂.
The web has been optimized for speed, engagement, and conversion.
Never for energy efficiency.
Because we couldn't measure it.
Now we can.
See the difference for yourself
The difference between the best and worst? Over 100x.
Same information. Same purpose. Vastly different impact.
You can't optimize
what you can't measure.
Now you can measure it.
Every page you visit. Graded A+ to F.
Real-time energy monitoring.
The invisible, finally visible.
For the curious: How it actually works
Technical details for developers and skeptics
Browser APIs we use
- Performance API — High-resolution timing and resource measurement
- PerformanceObserver — Real-time monitoring of long tasks
- Navigator API — Hardware concurrency and device memory
- WebGL — GPU identification via renderer string
- requestAnimationFrame — Frame rate and rendering load
The energy model
We combine three estimation methods:
- Time-based — Power correlates with CPU active time
- Activity-based — Different operations have different costs
- Calibrated — Adjusted by your device's measured performance
The final estimate weights each method by confidence.
Calibration process
We run standard benchmarks (Fibonacci, Mandelbrot, memory access) and compare:
- Your browser's execution time
- Our server's execution time (measured with powermetrics)
- The ratio becomes your calibration factor
Cached for 7 days, automatically refreshed.
Privacy & security
- 100% local — All analysis in your browser
- No tracking — We don't know what sites you visit
- No accounts — Install and use, nothing else
- Open source — Audit every line of code
- Minimal permissions — Only activeTab and storage