OpenAI Launches GPT-6 Sol and Luna With Lower Prices and Fewer Errors

OpenAI has announced two new models in its GPT-6 family, Sol and Luna, now available in the API, ChatGPT, and Codex for eligible paid plans, with a gradual rollout throughout the day to keep the service stable. Both models build on the capabilities of the larger GPT-6 Astra model, but in a smaller, faster form aimed at large-scale use.

The company cut API pricing by roughly half: GPT-6 Sol now costs $2 per million input tokens and $10 per million output tokens, down from $4 and $20 for its predecessor, GPT-5.6 Sol. The smaller GPT-6 Luna is priced at $0.10 per million input tokens and $0.50 per million output tokens. According to OpenAI's internal evaluation based on real conversations where users flagged mistakes, GPT-6 Sol makes roughly half as many errors as its predecessor, approaching the reliability of the larger Astra model at a much lower cost.

The move comes amid an intensifying race among major AI companies to cut inference costs while improving accuracy, after high prices and factual errors had been among the most common criticisms of the previous generation of models.