OpenAI launches GPT-6 Sol and Luna at half the price of predecessors

OpenAI has released GPT-6 Sol and GPT-6 Luna, two new models that sit below the flagship GPT-6 Astra introduced earlier this month. Both models are available now in ChatGPT Work, Codex, and via the API for Plus, Pro, Business, Enterprise, and Edu subscribers, while Free and Go users can access Luna on the desktop app.

Sol targets complex professional tasks and coding, whereas Luna is optimized for high-volume workloads such as summarization and information extraction. Both architectures are tuned for long-running workflows and AI agents.

“These savings are passed directly to users and customers.”

API pricing has been cut by 50% compared with the promotional GPT-5.6 rates. GPT-6 Sol now costs $2 per million input tokens and $10 per million output tokens, down from $4 and $20 respectively. GPT-6 Luna drops to $0.10 input and $0.50 output from $0.20 and $1.20.

Cached prompt reads receive a 90% discount, though Artificial Analysis notes a 25% surcharge for cache writes. OpenAI attributes the lower prices to caching and inference efficiency gains passed directly to customers.

Independent benchmarks show mixed performance results. Artificial Analysis estimates a per-task cost of $1.06 for Sol at its highest compute tier. OpenAI still recommends Astra for the most demanding tasks, pricing it at $10 input and $50 output per million tokens.