Skip to content
https://edf.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
66
GRADE
D
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
F
CO2 Per Page Load
Action
1.54g CO2 per view
FIX
1.54g CO2 per view
Warning::
1.54g CO2 per page view
This page transfers 5.4 MB, producing an estimated 1.54g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.29g, network 0.27g, end-user device 0.99g.
Got: 1.54g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 185.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 185.2 kg of CO2 annually — equivalent to charging 23148 smartphones.

1.54g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 24% of websites

Sustainable Web Design model v4 · Page size: 5.4 MB

Your site
1.54g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.29g
Network
0.27g
End-user device
0.99g
At 10,000 monthly views: Monthly: 15.4 kg · Annual: 185.2 kg · ≈ 23148 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
Info::
Green hosting status based on known provider commitments
Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.
Green HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
76th percentile
FIX
76th percentile
Warning::
1.54g CO2 — above the median website (0.60g)
Heavier than an estimated 24% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 76th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.54g

76th percentile

Cleaner than 24% of websites

✗ Above the median website

vs Median 157% more
vs Target 209% more
B
Transfer Efficiency
85% efficient
REVIEW
85% efficient
Info::
Transfer efficiency: 85%
An estimated 834 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 834 KB of unused JavaScript. This wasted data produces 0.23g of unnecessary CO2 per page view.
85% efficient

Total waste: 834 KB (15% of page weight)

Unused JS 834 KB

0.23g unnecessary CO2 per visit

Actual transfer 5579 KB
Theoretical minimum 4745 KB
Potential savings 834 KB (0.23g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
88% cached
PASS
88% cached
Info::
88% reduction on repeat visits
Returning visitors download only 655 KB (vs 5579 KB first visit). 266 of 286 resources are served from browser cache, saving 1.36g CO2 per repeat visit.
Info::
Repeat visit: 0.18g CO2 (first visit: 1.54g)
First visit
5579 KB
Repeat visit
655 KB

88% reduction on repeat visits

Saving 1.36g CO2 per returning visitor

266 resources served from cache · 20 resources re-downloaded

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback