Head to head

o3 vs GPT-5.1

On a blended workload of one million input tokens and three million output tokens, o3 is 1.2× cheaper than GPT-5.1.

o3GPT-5.1
Provider OpenAI OpenAI
Input / MTok $2 $1.25
Output / MTok $8 $10
Cache read / MTok $0.5 $0.125
Context window 200,000
Blended 1M in + 3M out $26.00 $31.25
Status ga ga

o3 detail   GPT-5.1 detail