Head to head

GPT-5.6 Luna vs GPT-5.5

On a blended workload of one million input tokens and three million output tokens, GPT-5.6 Luna is 25.0× cheaper than GPT-5.5.

GPT-5.6 LunaGPT-5.5
Provider OpenAI OpenAI
Input / MTok $0.2 $5
Output / MTok $1.2 $30
Cache read / MTok $0.02 $0.5
Context window
Blended 1M in + 3M out $3.80 $95.00
Status ga ga

GPT-5.6 Luna detail   GPT-5.5 detail