Sustainability

· 7 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

3 PASS 3 REVIEW 1 FIX

Carbon Budget

Action

53th percentile

FIX

53th percentile

0.73g CO2 — above the median website (0.60g)

Heavier than an estimated 47% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.

Estimated 53th percentile

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

Top 10%

Target

Median website

0.73g

53rd percentile

Cleaner than 47% of websites

✗ Above the median website

vs Median 22% more

vs Target 47% more

CO2 Per Page Load

0.73g CO2 per view

REVIEW

0.73g CO2 per view

0.73g CO2 per page view

This page transfers 3.1 MB, producing an estimated 0.73g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.15g, end-user device 0.56g.

Got: 0.73g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 88.1 kg CO2/year

With 10,000 page views per month, this page would generate approximately 88.1 kg of CO2 annually — equivalent to charging 11011 smartphones.

Green hosting reduces data center emissions

0.73g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 47% of websites

Sustainable Web Design model v4 · Page size: 3.1 MB

Your site

0.73g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.02g

Network

0.15g

End-user device

0.56g

At 10,000 monthly views: Monthly: 7.3 kg · Annual: 88.1 kg · ≈ 11011 smartphone charges

Web Font Weight Variants

No detectable Google Fonts weights

REVIEW

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Green Hosting

Green (both)

PASS

Green (both)

Both hosting and CDN use renewable energy

Got: Hosting: Vercel, CDN: Vercel

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

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 Vercel✓CDN Vercel✓

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+

Repeat Visit Weight

99% cached

PASS

99% cached

99% reduction on repeat visits

Returning visitors download only 38 KB (vs 3175 KB first visit). 77 of 79 resources are served from browser cache, saving 0.73g CO2 per repeat visit.

Repeat visit: 0.01g CO2 (first visit: 0.73g)

First visit

3175 KB

Repeat visit

38 KB

99% reduction on repeat visits

Saving 0.73g CO2 per returning visitor

77 resources served from cache · 2 resources re-downloaded

A+

Transfer Efficiency

94% efficient

PASS

94% efficient

Transfer efficiency: 94%

Only 182 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 182 KB (6% of page weight)

Unused JS 182 KB

0.04g unnecessary CO2 per visit

Actual transfer 3175 KB

Theoretical minimum 2993 KB

Potential savings 182 KB (0.04g CO2)

See Deep Analysis sections above for specific optimizations.

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