Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Device:

Mobile Desktop

Checks

5 PASS 2 REVIEW

Green Hosting

Green (hosting)

REVIEW

Green (hosting)

Hetzner Online GmbH uses renewable energy

Hetzner Online GmbH: Verified by the Green Web Foundation

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 Hetzner Online GmbH✓CDN Not identified✗

Hetzner Online GmbH: Verified by the Green Web Foundation

Based on known provider commitments. Verify at thegreenwebfoundation.org

Transfer Efficiency

80% efficient

REVIEW

80% efficient

Transfer efficiency: 80%

An estimated 228 KB (20%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 228 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.

Total waste: 228 KB (20% of page weight)

Unused JS 228 KB

0.05g unnecessary CO2 per visit

Actual transfer 1156 KB

Theoretical minimum 928 KB

Potential savings 228 KB (0.05g CO2)

See Deep Analysis sections above for specific optimizations.

CO2 Per Page Load

0.27g CO2 per view

PASS

0.27g CO2 per view

0.27g CO2 per page view

This page transfers 1.1 MB, producing an estimated 0.27g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.21g.

Got: 0.27g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 32.1 kg CO2/year

With 10,000 page views per month, this page would generate approximately 32.1 kg of CO2 annually — equivalent to charging 4009 smartphones.

Green hosting reduces data center emissions

0.27g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 84% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site

0.27g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.06g

End-user device

0.21g

At 10,000 monthly views: Monthly: 2.7 kg · Annual: 32.1 kg · ≈ 4009 smartphone charges

A+

Repeat Visit Weight

99% cached

PASS

99% cached

99% reduction on repeat visits

Returning visitors download only 16 KB (vs 1156 KB first visit). 32 of 36 resources are served from browser cache, saving 0.26g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.27g)

First visit

1156 KB

Repeat visit

16 KB

99% reduction on repeat visits

Saving 0.26g CO2 per returning visitor

32 resources served from cache · 4 resources re-downloaded

Carbon Budget

16th percentile

PASS

16th percentile

0.27g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 84% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 16th percentile

Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.

Top 10%

Target

Median website

0.27g

16th percentile

Cleaner than 84% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 55% cleaner ✓

vs Target 47% cleaner ✓

A+

Web Font Weight Variants

2 font weights loaded across 1 famil(y/ies) -- reasonable

PASS

2 font weights loaded across 1 famil(y/ies) -- reasonable

2 font weight(s) loaded across 1 famil(y/ies)

A+

Green Hosting

Whether the site is served from green-energy infrastructure

PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Hetzner Online GmbH

Image Optimization

9 images, 468 KB total, 364 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

468 KB

Oversized

Wasted

364 KB

9 missing dimensions 8 missing lazy loading

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