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https://www.storyblok.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
78
GRADE
C
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::
AWS CloudFront: Renewable varies by edge location
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 Amazon Web Services✗CDN AWS CloudFront✗

AWS CloudFront: Renewable varies by edge location

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
85% efficient
REVIEW
85% efficient
Info::
Transfer efficiency: 85%
An estimated 170 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 170 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
85% efficient

Total waste: 170 KB (15% of page weight)

Unused JS 170 KB

0.05g unnecessary CO2 per visit

Actual transfer 1113 KB
Theoretical minimum 942 KB
Potential savings 170 KB (0.05g 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
0.31g CO2 per view
PASS
0.31g CO2 per view
Info::
0.31g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.31g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.05g, end-user device 0.20g.
Got: 0.31g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 36.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 36.9 kg of CO2 annually — equivalent to charging 4617 smartphones.

0.31g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 80% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.31g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.05g
End-user device
0.20g
At 10,000 monthly views: Monthly: 3.1 kg · Annual: 36.9 kg · ≈ 4617 smartphone charges
A+
Repeat Visit Weight
95% cached
PASS
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 52 KB (vs 1113 KB first visit). 93 of 94 resources are served from browser cache, saving 0.29g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.31g)
First visit
1113 KB
Repeat visit
52 KB

95% reduction on repeat visits

Saving 0.29g CO2 per returning visitor

93 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
20th percentile
PASS
20th percentile
Info::
0.31g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 80% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 20th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.31g

20th percentile

Cleaner than 80% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 49% cleaner ✓
vs Target 38% 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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