openai.com

The numbers

First visit

1.03 g CO₂e

Return visit

0.017 g CO₂e

Hosting

verified green

LCP

508 ms

CLS

0

TTFB

156 ms

At 10,000 views a month this page emits about 93.4 kg CO₂e a year, roughly 383 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 2%, and world-average grid intensity. How we calculate this

1. Audit third-party servicessave ~0.143 g/visit (1.56 MB)High impact · moderate effort

   5 third-party domains account for 3.13 MB (37% 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.

   • images.ctfassets.net2.79 MB
   • ab.chatgpt.com324 kB
   • static.cloudflareinsights.com12 kB
   • chatgpt.com4.2 kB
   • cloudflareinsights.com184 B

   WSG 3.5: Treat third parties the same as first parties
2. Defer video and audiosave ~0.098 g/visit (1.07 MB)High impact · quick fix

   1.34 MB of audio/video downloads during initial page load; 3 videos autoplay.

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

   • chatgpt-5-6-model-slider-loop-v1.mp4671 kB
   • chatgpt-5-6-model-slider-loop-v1.mp4671 kB
   • OAI_ChatGPT_ModelBlog_ArtCard_1920x1080_compr…0 B
   • OAI_ChatGPT_ModelBlog_ArtCard_1920x1080_compr…0 B

   WSG 2.9: Optimize media to reduce resource use
3. Serve images at the size they displaysave ~0.083 g/visit (906 kB)High impact · quick fix

   14 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.

   • OpenAI_Ganassi_1x1.jpg472 kB
   • OpenAI_Falcon_1x1.jpg396 kB
   • 2026_04_Gardi_ProjectOwl_KittPeak_Day1_02144.jpg296 kB
   • price-performance-frontier_art-card_1x1.png276 kB
   • OpenAI_Presence_1x1.png207 kB

   WSG 2.9: Optimize media to reduce resource use
4. Reduce JavaScript payloadsave ~0.081 g/visit (887 kB)High impact · moderate effort

   85 scripts total 3.55 MB on the wire (11.59 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.

   • 0pknop5jh7c16.js316 kB
   • 11-l352cavcg-.js306 kB
   • 3u7_edvds38mk.js292 kB
   • 3wh0w50krhyv9.js235 kB
   • 3p2bilzxf6joo.js173 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
5. Convert and compress imagessave ~0.038 g/visit (414 kB)High impact · quick fix

   3 images exceed 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.

   • OpenAI_Ganassi_1x1.jpg472 kB
   • gpt-5-6-poster.png411 kB
   • OpenAI_Falcon_1x1.jpg396 kB

   WSG 2.9: Optimize media to reduce resource use
6. Fix caching for returning visitorssave ~0.0032 g/visit (27 kB)Medium impact · quick fix

   On a repeat visit 107 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.

   • v1Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0 · 80 kB
   • api.jsCache-Control: max-age=31536000, stale-if-error=10800, stale-while-revalidate=31536000, public · 27 kB

   WSG 4.2: Optimize caching and support offline access
7. Remove references to broken resourcessave ~0.0070 g/visit (76 kB)Advisory · quick fix

   12 requests answered 4xx/5xx on load: transfer and connections spent on nothing, on every single visit.

   Delete or fix the references (stale asset URLs, dead third-party tags). Each one is a request the page provably does not need.

   • businessHTTP 403 · 6.9 kB
   • apiHTTP 403 · 7.0 kB
   • aboutHTTP 403 · 7.0 kB
   • indexHTTP 403 · 6.9 kB
   • 3510127618HTTP 403 · 6.8 kB

   WSG 4.4: Setup necessary error pages and redirection links
8. Optimize web fontssave ~0.0053 g/visit (59 kB)Advisory · quick fix

   3 font files total 167 kB.

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

   • OpenAISans-Semibold.woff257 kB
   • OpenAISans-Medium.woff257 kB
   • OpenAISans-Regular.woff254 kB

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

   At 8.53 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

Where the bytes are

• JavaScript3.55 MB · 85 req
• Images2.79 MB · 15 req
• Audio / video1.34 MB · 4 req
• Data (fetch)405 kB · 18 req
• Fonts167 kB · 3 req
• HTML160 kB · 1 req
• CSS114 kB · 14 req
• Data (XHR)1.6 kB · 2 req
• Other0 B · 6 req