GPT-6 Luna

GPT-6 Luna is the smallest and cheapest model in OpenAI's GPT-6 family, released 2026-09-22. OpenRouter lists $0.1 per million input tokens and $0.5 output, with a 1,050,000-token context and text, image and PDF input, which matches the pricing on OpenAI's own page that we cite on our provider entry. It is closed and proprietary. We would suggest it for bulk jobs such as classification, extraction and routing, and for the default model in a chain where a larger one is called only when needed. The limit is that a model priced this low is not the one to trust with hard reasoning or long coding tasks, so test it on your own examples first. Prices and specifications come from the OpenRouter listing we checked on 31 October 2026, and we have not tested the model ourselves.