Head to head

GPT-5.4 nano vs GPT-5.6 Luna

On a blended workload of one million input tokens and three million output tokens, GPT-5.6 Luna is 1.0× cheaper than GPT-5.4 nano.

GPT-5.4 nanoGPT-5.6 Luna
Provider OpenAI OpenAI
Input / MTok $0.2 $0.2
Output / MTok $1.25 $1.2
Cache read / MTok $0.02 $0.02
Context window
Blended 1M in + 3M out $3.95 $3.80
Status ga ga

GPT-5.4 nano detail   GPT-5.6 Luna detail