ChatGPT o4-mini-high; 2025-05-17
On average, studies show that a heavyweight ad- and tracker-blocker like uBlock Origin saves around a third of the data you’d otherwise download – and in concrete terms:
- Bandwidth saved per page load
In a diverse set of real-world tests on hundreds of popular sites, the average bandwidth saving from ad- and tracker-blocking was 899 KB (with a median of just under 500 KB and a 95th-percentile of 2.76 MB) (Brave). This corresponds to roughly 25–34 % less data transferred compared with no blocker (arXiv). - CO₂e saved per page load
Network data transfer emits about 11 g CO₂e per GB downloaded (Sphera). So saving 0.0009 GB (899 KB) equates to roughly 0.01 g CO₂e per page.
Putting that in the context of everyday browsing:
| Pages per day | Data saved per day | CO₂e saved per day | CO₂e saved per year |
|---|---|---|---|
| 20 | ~18 MB | ~0.20 g CO₂e | ~73 g CO₂e |
| 40 | ~36 MB | ~0.40 g CO₂e | ~146 g CO₂e |
| 60 | ~54 MB | ~0.60 g CO₂e | ~219 g CO₂e |
So, a typical user loading 40 pages a day could save nearly 36 MB of bandwidth and avoid about 0.4 g of CO₂e emissions every day – that’s over 140 g CO₂e in a year, simply by blocking ads and trackers.