CO2Stats

How much carbon does a web page cost?

Enter the address of a page. We load it once in a real browser and weigh everything it downloads. Then we estimate the carbon each visit causes, with a published method.

Check a web page

Results are public: anyone with the link to a result can see it. Don’t check private pages, or links that carry a password or a token.

Each check loads one page once. The result is an estimate: how the checker works.

CO2 in the air

426.07 ppm

The average for September 2026, measured at Mauna Loa in Hawaii.

ppm (parts per million) is how many of every million molecules of dry air are carbon dioxide. The line is every monthly average since March 1958, when it was 315.71 ppm.

Source: NOAA, as of 16 October 2026.

See the full record

More to read

  • The Kettle Question

    Does an AI prompt boil a kettle? Published estimates of the energy and carbon of everyday digital life, with who made each one and what it counts.

  • Is your web host green?

    Each host’s listing with the Green Web Foundation, what that listing means, and the host’s own evidence, each checked and dated.

  • CO2 since you were born

    Compare the carbon dioxide in the air in the year you were born with the latest full year.

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