www.edwardtufte.com

The numbers

First visit

0.312 g CO₂e

Return visit

0.0042 g CO₂e

Hosting

verified green

LCP

1.05 s

CLS

0.001

TTFB

147 ms

At 10,000 views a month this page emits about 28.2 kg CO₂e a year, roughly 115 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 1%, and world-average grid intensity. How we calculate this

1. Audit third-party servicessave ~0.050 g/visit (546 kB)High impact · moderate effort

   12 third-party domains account for 1.09 MB (42% 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.

   • f.vimeocdn.com347 kB
   • www.googletagmanager.com344 kB
   • connect.facebook.net177 kB
   • ka-p.fontawesome.com139 kB
   • fonts.gstatic.com47 kB
   • i.vimeocdn.com20 kB

   WSG 3.5: Treat third parties the same as first parties
2. Serve images at the size they displaysave ~0.040 g/visit (443 kB)High impact · quick fix

   1 image is encoded at more than twice the pixels the layout shows, even accounting for this viewport's pixel density.

   Generate multiple sizes and let the browser pick with srcset/sizes; a 4000px original behind a 400px slot spends bandwidth no screen displays.

   • PDF-AI-License-Front-Page-1390x1536.jpg736 kB

   WSG 2.9: Optimize media to reduce resource use
3. Convert and compress imagessave ~0.040 g/visit (439 kB)High impact · quick fix

   2 images (323 kB) ship in legacy formats (JPEG/PNG/GIF); 1 image exceeds 300 kB apiece.

   Serve AVIF (or WebP) with responsive srcset sizes, and re-compress oversized files. AVIF typically halves JPEG weight at the same visual quality.

   • PDF-AI-License-Front-Page-1390x1536.jpg736 kB
   • footer-stone-sculpture.jpg166 kB
   • hogpen-hill-farms-sculptures-768x710.jpg157 kB

   WSG 2.9: Optimize media to reduce resource use
4. Reduce JavaScript payloadsave ~0.022 g/visit (245 kB)High impact · moderate effort

   25 scripts total 981 kB on the wire (3.41 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.

   • player.module.js226 kB
   • js187 kB
   • js157 kB
   • fbevents.js110 kB
   • vendor.module.js96 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
5. Lazy-load below-the-fold mediasave ~0.018 g/visit (195 kB)Medium impact · quick fix

   17 below-the-fold images/iframes (389 kB) download immediately for every visitor.

   Add loading="lazy" to below-fold img and iframe elements (and keep it off the LCP image). Browsers then fetch them only when scrolling approaches.

   • footer-stone-sculpture.jpg166 kB
   • edward-tufte-seeing-with-fresh-eyes-book.png142 kB
   • WavefieldsPicon4.png16 kB
   • FlameSm4.png14 kB
   • SeeingAround2.png11 kB

   WSG 2.9: Optimize media to reduce resource use
6. Collapse the redirect chainMedium impact · quick fix

   The address that was scanned goes through 2 redirects before the document is served, ending at https://www.edwardtufte.com/. 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://edwardtufte.com/redirects to https://www.edwardtufte.com/

   WSG 4.4: Setup necessary error pages and redirection links
7. Upgrade compression beyond gzipsave ~0.0061 g/visit (67 kB)Advisory · quick fix

   449 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.

   • fbevents.js110 kB
   • pro.min.css83 kB
   • 17601412286466367 kB
   • wpm-public__premium_only.p1.min.js53 kB
   • jquery.min.js31 kB

   WSG 4.3: Reduce data transfer with compression
8. Optimize web fontssave ~0.0029 g/visit (32 kB)Advisory · quick fix

   5 font files total 90 kB.

   Subset fonts to used glyphs, prefer one variable font over multiple weights, serve WOFF2 only, and consider system fonts for UI text.

   • S6uyw4BMUTPHjx4wXg.woff224 kB
   • S6u9w4BMUTPHh6UVSwiPGQ.woff223 kB
   • pro-fa-solid-900-12.woff217 kB
   • pro-fa-solid-900-1.woff214 kB
   • pro-fa-solid-900-0.woff212 kB

   WSG 2.11: Use optimized web typography
9. Set a page-weight budgetAdvisory · moderate effort

   At 2.57 MB per view this page rates D. 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

Where the bytes are

• Images1.31 MB · 24 req
• JavaScript981 kB · 25 req
• Data (fetch)96 kB · 8 req
• Fonts90 kB · 5 req
• CSS61 kB · 9 req
• HTML35 kB · 2 req
• Data (XHR)2.0 kB · 2 req