atlasderschweiz.ch/en

The numbers

First visit

0.435 g CO₂e

Return visit

<0.001 g CO₂e

Hosting

unknown

LCP

504 ms

CLS

0.062

TTFB

18 ms

At 10,000 views a month this page emits about 39.1 kg CO₂e a year, roughly 160 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 0%, and world-average grid intensity. How we calculate this

1. Reduce JavaScript payloadsave ~0.048 g/visit (433 kB)High impact · moderate effort

   98 scripts total 1.73 MB on the wire (5.55 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.

   • dist.Bx3OOhDk.js558 kB
   • tree.BCFN8EPs.js149 kB
   • astro.B9D2gW4p.js89 kB
   • astro.B9D2gW4p.js89 kB
   • i18n.W0En-dzY.js72 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
2. Audit third-party servicessave ~0.020 g/visit (183 kB)Medium impact · moderate effort

   3 third-party domains account for 365 kB (12% 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.

   • api.maptiler.com365 kB
   • 294 B
   • o4510260294123520.ingest.de.sentry.io281 B

   WSG 3.5: Treat third parties the same as first parties
3. Convert and compress imagessave ~0.019 g/visit (167 kB)Medium impact · quick fix

   11 images (372 kB) ship in legacy formats (JPEG/PNG/GIF).

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

   • 6a22daf765466c9d8294d126_hd.jpg121 kB
   • 6a5dfb4c7ed570e87eb7fe77.jpg73 kB
   • 6a575a03a6c77bde1757dca9.jpg51 kB
   • 6a60670ba46937eb850f4a60.jpg48 kB
   • 6a57ae81d4c319df0dbe25cf.jpg41 kB

   WSG 2.9: Optimize media to reduce resource use
4. 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
5. Upgrade compression beyond gzipsave ~0.031 g/visit (280 kB)Advisory · quick fix

   1.87 MB 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.

   • dist.Bx3OOhDk.js558 kB
   • tree.BCFN8EPs.js149 kB
   • astro.B9D2gW4p.js89 kB
   • astro.B9D2gW4p.js89 kB
   • i18n.W0En-dzY.js72 kB

   WSG 4.3: Reduce data transfer with compression
6. Stop downloading the same asset twicesave ~0.022 g/visit (200 kB)Advisory · quick fix

   9 assets were fetched more than once in a single page load (334 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.

   • i18n.W0En-dzY.js2 downloads · 145 kB
   • translation.DJdfSRe5.js2 downloads · 1.7 kB
   • rolldown-runtime.aKtaBQYM.js2 downloads · 1.9 kB
   • vendor.gqnlCVSr.js2 downloads · 139 kB
   • utils.BdNvQAsE.js2 downloads · 125 kB

   WSG 3.2: Minify and remove unused code
7. Optimize web fontssave ~0.0099 g/visit (89 kB)Advisory · quick fix

   3 font files total 254 kB.

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

   • 80d80c8a.CHKc-8Dx.woff285 kB
   • 6d461439.mwgJxkG-.woff285 kB
   • 71848623.D38PiE1w.woff285 kB

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

   At 2.93 MB per view this page rates E. 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

• JavaScript1.73 MB · 98 req
• Data (fetch)459 kB · 15 req
• Images426 kB · 16 req
• Fonts254 kB · 3 req
• HTML42 kB · 2 req
• CSS19 kB · 1 req
• Other294 B · 7 req