GPT-5.6 Luna vs Mistral Large 3

OpenAI against Mistral AI, costed on the same three workloads. GPT-5.6 Luna is cheaper on all three workloads.

Monthly bill, side by side

WorkloadGPT-5.6 LunaMistral Large 3Difference
Support chatbot
2,500 six-turn conversations a day
$887 $1,609 $722 (1.8×)
Document summariser
1,000 single-shot summaries a day
$102 $219 $117 (2.1×)
Coding agent
200 twelve-turn sessions a day
$598 $1,224 $626 (2×)

No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.

The rate cards

GPT-5.6 LunaMistral Large 3
Input, per 1M tokens$0.2$0.5
Output, per 1M tokens$1.2$1.5
Cached input$0.02not published
Context window1.05M262K
Maximum output128K262K
Reasoning modelyesno
Visionyesyes

Run this comparison on your own numbers

Full detail: GPT-5.6 Luna pricing · Mistral Large 3 pricing