www.netcup.com/en

The numbers

First visit

0.334 g CO₂e

Return visit

0.016 g CO₂e

Hosting

unknown

LCP

440 ms

CLS

0.01

TTFB

225 ms

At 10,000 views a month this page emits about 30.6 kg CO₂e a year, roughly 125 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 5%, and world-average grid intensity. How we calculate this

1. Serve images at the size they displaysave ~0.046 g/visit (409 kB)High impact · quick fix

   4 images are 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.

   • large_startseiten_header_VPS_x86_v02_2926352a…626 kB
   • HOTY_V_Server_1_netcup_1_06076f4f7f.png62 kB
   • nc_WHDJ_26_Blog_1046x746_EN_9a062e6697.png35 kB
   • SP_2025_b739192e90.png22 kB

   WSG 2.9: Optimize media to reduce resource use
2. Convert and compress imagessave ~0.040 g/visit (353 kB)High impact · quick fix

   7 images (784 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.

   • large_startseiten_header_VPS_x86_v02_2926352a…626 kB
   • HOTY_V_Server_1_netcup_1_06076f4f7f.png62 kB
   • nc_WHDJ_26_Blog_1046x746_EN_9a062e6697.png35 kB
   • SP_2025_b739192e90.png22 kB
   • 5eur_voucher_png222_5a93177dae.png19 kB

   WSG 2.9: Optimize media to reduce resource use
3. Reduce JavaScript payloadsave ~0.033 g/visit (296 kB)High impact · moderate effort

   131 scripts total 1.18 MB on the wire (3.48 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.

   • B0myLyiM.js207 kB
   • js184 kB
   • nstm.js175 kB
   • js160 kB
   • otBannerSdk.js131 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
4. Audit third-party servicessave ~0.020 g/visit (180 kB)Medium impact · moderate effort

   5 third-party domains account for 359 kB (16% 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.

   • cdn.cookielaw.org199 kB
   • www.googletagmanager.com160 kB
   • geolocation.onetrust.com282 B
   • 0 B
   • pagead2.googlesyndication.com0 B

   WSG 3.5: Treat third parties the same as first parties
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. 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.netcup.com/en. 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://netcup.com/redirects to https://www.netcup.com/en

   WSG 4.4: Setup necessary error pages and redirection links
7. Upgrade compression beyond gzipsave ~0.021 g/visit (187 kB)Advisory · quick fix

   1.24 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.

   • B0myLyiM.js207 kB
   • js184 kB
   • nstm.js175 kB
   • otBannerSdk.js131 kB
   • netcup.com108 kB

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

   At 2.26 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
9. Simplify the document structureAdvisory · larger effort

   The page renders 6888 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

• JavaScript1.18 MB · 131 req
• Images839 kB · 20 req
• HTML108 kB · 1 req
• Data (fetch)48 kB · 14 req
• Fonts38 kB · 3 req
• CSS35 kB · 34 req
• Data (XHR)2.8 kB · 2 req