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https://rentry.co

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
92
GRADE
A
FIX
0
REVIEW
1
PASS
5
INFO
0
Device:
Mobile Desktop
Checks
6
5 PASS 1 REVIEW
C
Transfer Efficiency
Action
70% efficient
REVIEW
70% efficient
Warning::
Transfer efficiency: 70%
An estimated 105 KB (30%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 105 KB of unused JavaScript. This wasted data produces 0.02g of unnecessary CO2 per page view.
70% efficient

Total waste: 105 KB (30% of page weight)

Unused JS 105 KB

0.02g unnecessary CO2 per visit

Actual transfer 355 KB
Theoretical minimum 250 KB
Potential savings 105 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

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 0.00g, network 0.02g, end-user device 0.06g.
Got: 0.08g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 9.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 9.9 kg of CO2 annually — equivalent to charging 1234 smartphones.
Info::
Green hosting reduces data center emissions

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
0.00g
Network
0.02g
End-user device
0.06g
At 10,000 monthly views: Monthly: 0.8 kg · Annual: 9.9 kg · ≈ 1234 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Cloudflare✓CDN Cloudflare✓

Cloudflare: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
95% cached
PASS
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 16 KB (vs 355 KB first visit). 17 of 18 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
355 KB
Repeat visit
16 KB

95% reduction on repeat visits

Saving 0.08g CO2 per returning visitor

17 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 ✓
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

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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