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

Green Hosting

Action

Unknown

FIX

Unknown

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.

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

Transfer Efficiency

81% efficient

REVIEW

81% efficient

Transfer efficiency: 81%

An estimated 269 KB (19%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 269 KB of unused JavaScript. This wasted data produces 0.07g of unnecessary CO2 per page view.

Total waste: 269 KB (19% of page weight)

Unused JS 269 KB

0.07g unnecessary CO2 per visit

Actual transfer 1388 KB

Theoretical minimum 1118 KB

Potential savings 269 KB (0.07g CO2)

See Deep Analysis sections above for specific optimizations.

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

0.38g CO2 per view

PASS

0.38g CO2 per view

0.38g CO2 per page view

This page transfers 1.4 MB, producing an estimated 0.38g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.07g, network 0.07g, end-user device 0.25g.

Got: 0.38g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 46.1 kg CO2/year

With 10,000 page views per month, this page would generate approximately 46.1 kg of CO2 annually — equivalent to charging 5758 smartphones.

0.38g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 72% of websites

Sustainable Web Design model v4 · Page size: 1.4 MB

Your site

0.38g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.07g

Network

0.07g

End-user device

0.25g

At 10,000 monthly views: Monthly: 3.8 kg · Annual: 46.1 kg · ≈ 5758 smartphone charges

A+

Repeat Visit Weight

99% cached

PASS

99% cached

99% reduction on repeat visits

Returning visitors download only 8 KB (vs 1388 KB first visit). 117 of 118 resources are served from browser cache, saving 0.38g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.38g)

First visit

1388 KB

Repeat visit

8 KB

99% reduction on repeat visits

Saving 0.38g CO2 per returning visitor

117 resources served from cache · 1 resources re-downloaded

Carbon Budget

28th percentile

PASS

28th percentile

0.38g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 72% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 28th percentile

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

Top 10%

Target

Median website

0.38g

28th percentile

Cleaner than 72% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 36% cleaner ✓

vs Target 23% cleaner ✓

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