www.build3.org

The numbers

First visit

0.737 g CO₂e

Return visit

0.028 g CO₂e

Hosting

unknown

LCP

1.37 s

CLS

0.009

TTFB

12 ms

At 10,000 views a month this page emits about 67.1 kg CO₂e a year, roughly 275 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 4%, and world-average grid intensity. How we calculate this

1. Audit third-party servicessave ~0.263 g/visit (2.34 MB)High impact · moderate effort

   23 third-party domains account for 4.68 MB (94% of the page).

   Remove services that no longer earn their place; load the rest on interaction (facades for embeds, delayed consent-gated tags). Each third party is also a privacy and performance dependency.

   • www.googletagmanager.com1.44 MB
   • video.wixstatic.com1.32 MB
   • static.parastorage.com948 kB
   • maps.googleapis.com434 kB
   • siteassets.parastorage.com219 kB
   • static.wixstatic.com133 kB

   WSG 3.5: Treat third parties the same as first parties
2. Reduce JavaScript payloadsave ~0.082 g/visit (727 kB)High impact · moderate effort

   124 scripts total 2.91 MB on the wire (9.48 MB decoded). Bundles this size usually carry a lot of unused code.

   Split bundles per route, tree-shake dependencies, and audit with a bundle analyzer or coverage profile. A 25% cut is a conservative target for bundles this size.

   • js383 kB
   • js194 kB
   • js194 kB
   • js194 kB
   • js193 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
3. Defer video and audiosave ~0.074 g/visit (662 kB)High impact · quick fix

   1.32 MB of audio/video downloads during initial page load; 1 video autoplays.

   Never autoload media: use preload="none" with a poster image, load players on interaction, and stream in an efficient codec (AV1/HEVC).

   • file.mp41.32 MB

   WSG 2.9: Optimize media to reduce resource use
4. Fix caching for returning visitorssave ~0.0061 g/visit (41 kB)Medium impact · quick fix

   On a repeat visit 163 kB of static assets were re-downloaded instead of coming from cache.

   Serve static assets with Cache-Control: public, max-age=31536000, immutable and versioned filenames so returning visitors download almost nothing.

   • jsCache-Control: private, max-age=900 · 162 kB
   • lop7iyulvzCache-Control: no-cache, no-store · 859 B
   • index.jsCache-Control: max-age=3600 · 318 B
   • panoramaCache-Control: no-cache · 153 B

   WSG 4.2: Optimize caching and support offline access
5. Verify your hosting energyMedium impact · moderate effort

   This host has not published renewable energy evidence with the Green Web Foundation, so its energy source is unknown.

   Choose a provider listed in the Green Web Directory, or ask your current provider to publish evidence (and a carbon.txt). This cuts the data-center share of every single page view.

   • carbon.txtNo carbon.txt found at the site root; publishing one is the lightest first step.

   WSG 4.1: Use sustainable hosting
6. Stop downloading the same asset twicesave ~0.021 g/visit (189 kB)Advisory · quick fix

   8 assets were fetched more than once in a single page load (693 kB of repeated transfer).

   Usually a script injected twice or cache-busting query strings that differ per reference. Load each asset once and let the HTTP cache do its job.

   • gtm.js2 downloads · 311 kB
   • bulklog4 downloads · 933 B
   • thunderbolt4 downloads · 201 kB
   • js2 downloads · 387 kB
   • js2 downloads · 387 kB

   WSG 3.2: Minify and remove unused code
7. Upgrade compression beyond gzipsave ~0.012 g/visit (104 kB)Advisory · quick fix

   694 kB of text ships gzip-compressed; Brotli or Zstandard would cut roughly another 15-20%, and browsers without them fall back to gzip automatically.

   Serve precompressed Brotli for static text assets (highest level, compressed at build time) and enable Brotli or zstd for dynamic responses; keep gzip only as the fallback.

   • js383 kB
   • thunderbolt51 kB
   • thunderbolt50 kB
   • thunderbolt50 kB
   • thunderbolt50 kB

   WSG 4.3: Reduce data transfer with compression
8. Set a page-weight budgetAdvisory · moderate effort

   At 4.97 MB per view this page rates F. The findings above list where the weight is.

   Agree a transfer budget (e.g. under 975 kB reaches a B), enforce it in CI, and re-scan after each change to hold the line.

   WSG 3.1: Set goals based on performance and energy impact
9. Remove the entry redirectAdvisory · quick fix

   The address that was scanned goes through 1 redirect before the document is served, ending at https://www.build3.org/. Every hop is a full round trip on a connection that has not warmed up yet.

   Point links, sitemaps and canonical tags at the final address, and make the host redirect in one hop rather than chaining http to https to www.

   • https://build3.org/redirects to https://www.build3.org/

   WSG 4.4: Setup necessary error pages and redirection links
10. Simplify the document structureAdvisory · larger effort

    The page renders 1656 DOM elements, above the 1,500 guideline. Large trees cost memory and CPU on every visitor's device.

    Flatten wrapper markup, render long lists virtually or paginate, and prefer semantic elements over nested divs.

    WSG 3.6: Ensure code follows good semantic practices

Where the bytes are

• JavaScript2.91 MB · 124 req
• Audio / video1.32 MB · 1 req
• HTML270 kB · 3 req
• Data (fetch)137 kB · 18 req
• Images130 kB · 41 req
• Other123 kB · 20 req
• Fonts73 kB · 4 req
• Data (XHR)3.9 kB · 4 req