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https://openjdk.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
84
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 REVIEW 1 FIX
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
Info::
Akamai: Committed to 50% renewable by 2030
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 HostingNot Green Hosted
Hosting Not identified✗CDN Akamai✗

Akamai: Committed to 50% renewable by 2030

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 37 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 37 KB of unused JavaScript. This wasted data produces 0.01g of unnecessary CO2 per page view.
87% efficient

Total waste: 37 KB (13% of page weight)

Unused JS 37 KB

0.01g unnecessary CO2 per visit

Actual transfer 295 KB
Theoretical minimum 258 KB
Potential savings 37 KB (0.01g 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+
CO2 Per Page Load
0.08g CO2 per view
PASS
0.08g CO2 per view
Info::
0.08g CO2 per page view
This page transfers 0.3 MB, producing an estimated 0.08g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.01g, end-user device 0.05g.
Got: 0.08g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 9.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 9.8 kg of CO2 annually — equivalent to charging 1224 smartphones.

0.08g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.3 MB

Your site
0.08g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.01g
End-user device
0.05g
At 10,000 monthly views: Monthly: 0.8 kg · Annual: 9.8 kg · ≈ 1224 smartphone charges
A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 6 KB (vs 295 KB first visit). 25 of 26 resources are served from browser cache, saving 0.08g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.08g)
First visit
295 KB
Repeat visit
6 KB

98% reduction on repeat visits

Saving 0.08g CO2 per returning visitor

25 resources served from cache · 1 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.08g 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

0.08g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 86% cleaner ✓
vs Target 84% cleaner ✓
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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