Stanford HAI Index Report 2026

Page 38 has an interesting comparison saying a session of 8 "medium length" messages uses roughly 10Wh, the equivalent of ~2 phone charges. The data dashboard[1] I think is defining medium length as 1000 tokens in, 1000 tokens out. And the page before suggests GPT-5 mini (medium) used 3x the energy of GPT-4o (Aug) which I guess I assumed would be the opposite ratio.

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I guess these estimates are based on calculations for gpt-4o (Aug) from Jegham et al[2] in November 2025.

[1]:https://app.powerbi.com/view?r=eyJrIjoiZjVmOTI0MmMtY2U2Mi00Z...

[2]:https://arxiv.org/pdf/2505.09598

[dupe] https://news.ycombinator.com/item?id=47758028