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https://tomdawayhet.com

Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
87
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
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗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
0.20g CO2 per view
PASS
0.20g CO2 per view
Info::
0.20g CO2 per page view
This page transfers 0.7 MB, producing an estimated 0.20g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.04g, end-user device 0.13g.
Got: 0.20g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 24.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 24.4 kg of CO2 annually — equivalent to charging 3049 smartphones.

0.20g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.7 MB

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

Energy Breakdown

Data center
0.04g
Network
0.04g
End-user device
0.13g
At 10,000 monthly views: Monthly: 2.0 kg · Annual: 24.4 kg · ≈ 3049 smartphone charges
A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 7 KB (vs 735 KB first visit). 16 of 17 resources are served from browser cache, saving 0.20g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.20g)
First visit
735 KB
Repeat visit
7 KB

99% reduction on repeat visits

Saving 0.20g CO2 per returning visitor

16 resources served from cache · 1 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.20g 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

0.20g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 66% cleaner ✓
vs Target 59% cleaner ✓
A+
Transfer Efficiency
100% efficient
PASS
100% efficient
Info::
Transfer efficiency: 100%
Only 0 KB of potential savings identified. Your page is well-optimized for size.
100% efficient
Actual transfer 735 KB
Theoretical minimum 735 KB

See Deep Analysis sections above for specific optimizations.

Image Optimization
5 images, 0 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

5

Total Size

0 KB

5 missing dimensions 1 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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