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Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
81
GRADE
B
FIX
1
REVIEW
2
PASS
4
INFO
1
Device:
Mobile Desktop
Checks
8
4 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::
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 Apache Traffic Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Web Font Weight Variants
No detectable Google Fonts weights
REVIEW
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
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
0.32g CO2 per view
PASS
0.32g CO2 per view
Info::
0.32g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.32g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.21g.
Got: 0.32g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 38.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 38.5 kg of CO2 annually — equivalent to charging 4815 smartphones.

0.32g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 78% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.32g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.06g
End-user device
0.21g
At 10,000 monthly views: Monthly: 3.2 kg · Annual: 38.5 kg · ≈ 4815 smartphone charges
A+
Repeat Visit Weight
90% cached
PASS
90% cached
Info::
90% reduction on repeat visits
Returning visitors download only 110 KB (vs 1160 KB first visit). 99 of 100 resources are served from browser cache, saving 0.29g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 0.32g)
First visit
1160 KB
Repeat visit
110 KB

90% reduction on repeat visits

Saving 0.29g CO2 per returning visitor

99 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
22th percentile
PASS
22th percentile
Info::
0.32g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 78% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 22th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.32g

22nd percentile

Cleaner than 78% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 46% cleaner ✓
vs Target 36% cleaner ✓
A+
Transfer Efficiency
93% efficient
PASS
93% efficient
Info::
Transfer efficiency: 93%
Only 80 KB of potential savings identified. Your page is well-optimized for size.
93% efficient

Total waste: 80 KB (7% of page weight)

Unused JS 80 KB

0.02g unnecessary CO2 per visit

Actual transfer 1160 KB
Theoretical minimum 1080 KB
Potential savings 80 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization
57 images, 600 KB total, 51 KB wasted
INFO

Image Optimization Audit

Total Images

57

Total Size

600 KB

Oversized

13

Wasted

51 KB

22 missing alt text 1 missing dimensions 49 missing lazy loading
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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