Head to head

Claude Sonnet 5 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 Claude Sonnet 5.

Claude Sonnet 5GPT-5.1
Provider Anthropic OpenAI
Input / MTok $2 $1.25
Output / MTok $10 $10
Cache read / MTok $0.2 $0.125
Context window 1,000,000
Blended 1M in + 3M out $32.00 $31.25
Status ga ga

Claude Sonnet 5 detail   GPT-5.1 detail