Skip to content
https://calibre-ebook.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
79
GRADE
C
FIX
0
REVIEW
3
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 3 REVIEW
B
Green Hosting
Green (hosting)
REVIEW
Green (hosting)
Info::
GoDaddy uses renewable energy
Info::
GoDaddy: 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 GoDaddy✓CDN Not identified✗

GoDaddy: Verified by the Green Web Foundation

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Carbon Budget
38th percentile
REVIEW
38th percentile
Info::
0.49g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 62% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 38th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.49g

38th percentile

Cleaner than 62% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 19% cleaner ✓
vs Target 3% cleaner ✓
C
Transfer Efficiency
Action
65% efficient
REVIEW
65% efficient
Warning::
Transfer efficiency: 65%
An estimated 734 KB (35%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 734 KB of unused JavaScript. This wasted data produces 0.17g of unnecessary CO2 per page view.
65% efficient

Total waste: 734 KB (35% of page weight)

Unused JS 734 KB

0.17g unnecessary CO2 per visit

Actual transfer 2099 KB
Theoretical minimum 1365 KB
Potential savings 734 KB (0.17g CO2)

See Deep Analysis sections above for specific optimizations.

A
CO2 Per Page Load
0.49g CO2 per view
PASS
0.49g CO2 per view
Info::
0.49g CO2 per page view
This page transfers 2.1 MB, producing an estimated 0.49g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.10g, end-user device 0.37g.
Got: 0.49g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 58.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 58.2 kg of CO2 annually — equivalent to charging 7278 smartphones.
Info::
Green hosting reduces data center emissions

0.49g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 62% of websites

Sustainable Web Design model v4 · Page size: 2.1 MB

Your site
0.49g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.10g
End-user device
0.37g
At 10,000 monthly views: Monthly: 4.9 kg · Annual: 58.2 kg · ≈ 7278 smartphone charges
A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 22 KB (vs 2099 KB first visit). 54 of 56 resources are served from browser cache, saving 0.48g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.49g)
First visit
2099 KB
Repeat visit
22 KB

99% reduction on repeat visits

Saving 0.48g CO2 per returning visitor

54 resources served from cache · 2 resources re-downloaded

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: OVHcloud

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

Send Feedback