nextjs.org/conf

The numbers

First visit

0.532 g CO₂e

Return visit

0.018 g CO₂e

Hosting

unknown

LCP

676 ms

CLS

n/a

TTFB

13 ms

At 10,000 views a month this page emits about 48.4 kg CO₂e a year, roughly 198 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 3%, and world-average grid intensity. How we calculate this

1. Reduce JavaScript payloadsave ~0.085 g/visit (753 kB)High impact · moderate effort

   37 scripts total 3.01 MB on the wire (9.47 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.

   • 1bjiuv-03hebu.js1.00 MB
   • 0plaj6zfr6p71.js306 kB
   • 1na4uwgdmhpwz.js277 kB
   • 3zy9fxizdclml.js243 kB
   • 2wpnujnkxxdd6.js191 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
2. 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.

   WSG 4.1: Use sustainable hosting
3. Optimize web fontssave ~0.0064 g/visit (57 kB)Advisory · quick fix

   4 font files total 163 kB.

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

   • Geist_Variable-s.p.2v-cf9syxr5ni.woff273 kB
   • GeistPixel_Square.p.3ig4wtfmw09gh.woff232 kB
   • GeistPixel_Circle.p.2p5mi6n8co77s.woff232 kB
   • 797e433ab948586e.p.1v5bejj26fx9h.woff226 kB

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

   At 3.59 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
5. Remove the entry redirectAdvisory · quick fix

   The address that was scanned goes through 1 redirect before the document is served. 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.

   WSG 4.4: Setup necessary error pages and redirection links

Where the bytes are

• JavaScript3.01 MB · 37 req
• Images198 kB · 47 req
• Fonts163 kB · 4 req
• CSS87 kB · 3 req
• Data (fetch)59 kB · 8 req
• Other40 kB · 2 req
• HTML32 kB · 1 req