Skip to content
https://gentoo.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
97
GRADE
A+
FIX
0
REVIEW
1
PASS
5
INFO
0
Checks
6
5 PASS 1 REVIEW
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
CO2 Per Page Load
0.14g CO2 per view
PASS
0.14g CO2 per view
Info::
0.14g CO2 per page view
This page transfers 0.6 MB, producing an estimated 0.14g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.03g, end-user device 0.11g.
Got: 0.14g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 16.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 16.9 kg of CO2 annually — equivalent to charging 2109 smartphones.
Info::
Green hosting reduces data center emissions

0.14g

Carbon Footprint per page view

Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.6 MB

Your site
0.14g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.00g
Network
0.03g
End-user device
0.11g
At 10,000 monthly views: Monthly: 1.4 kg · Annual: 16.9 kg · ≈ 2109 smartphone charges
A
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Fastly CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Fastly: 100% renewable energy for edge network
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 Hosting Green Hosted
Hosting Not identifiedCDN Fastly

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 5 KB (vs 608 KB first visit). 22 of 23 resources are served from browser cache, saving 0.14g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.14g)
First visit
608 KB
Repeat visit
5 KB

99% reduction on repeat visits

Saving 0.14g CO2 per returning visitor

22 resources served from cache · 1 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.14g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.14g

10th percentile

Cleaner than 90% of websites

Below the Web Sustainability Guidelines target

vs Median 77% cleaner ✓
vs Target 72% cleaner ✓
A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 21 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 21 KB (3% of page weight)

Unused JS 21 KB

0.00g unnecessary CO2 per visit

Actual transfer 608 KB
Theoretical minimum 587 KB
Potential savings 21 KB (0.00g CO2)

See Deep Analysis sections above for specific optimizations.

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

Send Feedback