Head to head

GPT-4o vs GPT-5.1

On a blended workload of one million input tokens and three million output tokens, GPT-5.1 is 1.0× cheaper than GPT-4o.

GPT-4oGPT-5.1
Provider OpenAI OpenAI
Input / MTok $2.5 $1.25
Output / MTok $10 $10
Cache read / MTok $1.25 $0.125
Context window 128,000
Blended 1M in + 3M out $32.50 $31.25
Status ga ga

GPT-4o detail   GPT-5.1 detail