OpenAI Reduces API Prices for GPT-5.6 Model Family
OpenAI has announced a price reduction for its GPT-5.6 model family, including Sol, Terra, and Luna, offering a 20% discount on inputs and a 33% discount on outputs. This promotional pricing is scheduled to remain in effect until at least November 21, 2026. This price cut intensifies the ongoing price war among frontier LLM providers, making high-intelligence models significantly more cost-effective compared to competitors like Anthropic. It lowers the barrier to entry for developers building complex reasoning and high-volume agentic applications. Under the new pricing, the flagship GPT-5.6 Sol costs $4.00 per million input tokens and $20.00 per million output tokens, while the lightweight Luna model costs just $0.20 for inputs and $1.20 for outputs. The pricing also includes discounted rates for cached inputs to help developers further optimize their API costs.
## BACKGROUND
OpenAI's GPT-5.6 series consists of three distinct models tailored for different use cases: Sol for advanced reasoning and coding, Terra for balanced performance and cost, and Luna for fast, high-volume tasks. These models compete directly with other frontier LLMs, such as Anthropic's Claude series, in benchmarks measuring intelligence, speed, and cost.