Model Comparison
GPT-5 vs o3 (Reasoning)
GPT-5: Very heavyo3 (Reasoning): Very heavy
Side-by-side environmental impact comparison. o3 (Reasoning) uses 17% more energy per query.
o3 (Reasoning) uses 17% more energy than GPT-5
21.4 Wh vs 18.4 Wh per query · 10.0 g vs 8.0 g CO₂ · 77 mL vs 66 mL water
GPT-5
OpenAI
Energy per query18.4 Wh
CO₂ per query8.0 g
Water per query66 mL
VS
o3 (Reasoning)
OpenAI
Energy per query21.4 Wh
CO₂ per query10.0 g
Water per query77 mL
GPT-5
ProviderOpenAI
CategoryText / Chat
Inference LocationAzure / Multi-cloud
Confidencepeer-reviewed
Efficiency TierVery heavy
o3 (Reasoning)
ProviderOpenAI
CategoryText / Chat
Inference LocationAzure US East / Sweden
Confidencepeer-reviewed
Efficiency TierVery heavy
Frequently Asked Questions
Which uses more energy, GPT-5 or o3 (Reasoning)?
o3 (Reasoning) uses 17% more energy per query than GPT-5. GPT-5 uses 18.4 Wh per query, while o3 (Reasoning) uses 21.4 Wh.
What is the carbon footprint difference between GPT-5 and o3 (Reasoning)?
o3 (Reasoning) uses 25% more CO₂ per query than GPT-5. GPT-5 emits 8.0 g of CO₂ per query compared to o3 (Reasoning)'s 10.0 g.
Which is more environmentally friendly, GPT-5 or o3 (Reasoning)?
GPT-5 is the more environmentally friendly option, using 18.4 Wh per query compared to o3 (Reasoning)'s 21.4 Wh. That makes o3 (Reasoning) roughly 1.2x more energy-intensive.
Calculate your footprint with these models
See how your daily usage of GPT-5 and o3 (Reasoning) adds up over time. Our calculator estimates energy, carbon, and water impact.
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