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

4 PASS 2 REVIEW 1 FIX

Green Hosting

Action

Not green

FIX

Not green

No confirmed renewable energy commitment detected

Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.

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 HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

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

CO2 Per Page Load

0.35g CO2 per view

PASS

0.35g CO2 per view

0.35g CO2 per page view

This page transfers 1.2 MB, producing an estimated 0.35g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.22g.

Got: 0.35g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 41.7 kg CO2/year

With 10,000 page views per month, this page would generate approximately 41.7 kg of CO2 annually — equivalent to charging 5212 smartphones.

0.35g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 76% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site

0.35g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.06g

Network

0.06g

End-user device

0.22g

At 10,000 monthly views: Monthly: 3.5 kg · Annual: 41.7 kg · ≈ 5212 smartphone charges

A+

Repeat Visit Weight

100% cached

PASS

100% cached

100% reduction on repeat visits

Returning visitors download only 4 KB (vs 1256 KB first visit). 28 of 29 resources are served from browser cache, saving 0.35g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.35g)

First visit

1256 KB

Repeat visit

4 KB

100% reduction on repeat visits

Saving 0.35g CO2 per returning visitor

28 resources served from cache · 1 resources re-downloaded

Carbon Budget

24th percentile

PASS

24th percentile

0.35g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 76% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 24th percentile

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

Top 10%

Target

Median website

0.35g

24th percentile

Cleaner than 76% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 42% cleaner ✓

vs Target 31% cleaner ✓

A+

Transfer Efficiency

94% efficient

PASS

94% efficient

Transfer efficiency: 94%

Only 76 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 76 KB (6% of page weight)

Unused JS 76 KB

0.02g unnecessary CO2 per visit

Actual transfer 1256 KB

Theoretical minimum 1180 KB

Potential savings 76 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

2 images, 853 KB total, 817 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

853 KB

Oversized

Wasted

817 KB

2 missing dimensions

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