https://wsws.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
72
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
DCO2 Per Page LoadAction1.39g CO2 per viewFIX
CO2 Per Page Load
Action1.39g CO2 per view
1.39g CO2 per view
Warning::
1.39g CO2 per page view
This page transfers 5.9 MB, producing an estimated 1.39g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.29g, end-user device 1.07g.
Got: 1.39g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 166.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 166.4 kg of CO2 annually — equivalent to charging 20805 smartphones.
Info::
Green hosting reduces data center emissions
1.39g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 28% of websites
Sustainable Web Design model v4 · Page size: 5.9 MB
Your site
1.39g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.03g
Network
0.29g
End-user device
1.07g
At 10,000 monthly views: Monthly: 13.9 kg · Annual: 166.4 kg · ≈ 20805 smartphone charges
FCarbon BudgetAction72th percentileFIX
Carbon Budget
Action72th percentile
72th percentile
Warning::
1.39g CO2 — above the median website (0.60g)
Heavier than an estimated 28% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 72th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.39g
72nd percentile
Cleaner than 28% of websites
✗ Above the median website
vs Median 131% more
vs Target 177% more
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Next.js uses renewable energy
Info::
Next.js: Verified by the Green Web Foundation
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 Next.js✓CDN Not identified✗
Next.js: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight95% cachedPASS
Repeat Visit Weight
95% cached
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 327 KB (vs 6000 KB first visit). 85 of 86 resources are served from browser cache, saving 1.31g CO2 per repeat visit.
Info::
Repeat visit: 0.08g CO2 (first visit: 1.39g)
First visit
6000 KB
Repeat visit
327 KB
95% reduction on repeat visits
Saving 1.31g CO2 per returning visitor
85 resources served from cache · 1 resources re-downloaded
A+Transfer Efficiency92% efficientPASS
Transfer Efficiency
92% efficient
92% efficient
Info::
Transfer efficiency: 92%
Only 462 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 462 KB (8% of page weight)
Unused JS 462 KB
0.11g unnecessary CO2 per visit
Actual transfer 6000 KB
Theoretical minimum 5538 KB
Potential savings 462 KB (0.11g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Hetzner Online GmbH
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.