GPT-5.6 Preview
Limited preview of the GPT-5.6 series
OpenAI’s limited preview release of the GPT-5.6 language-model series, comprising Sol (flagship), Terra (lower-cost), and Luna (fast, cost-efficient), initially for selected trusted partners through the API and Codex.
Pricing
Current GPT-5.6 Sol API rates: $4 per 1M input tokens, $20 per 1M output tokens, and $0.40 per 1M cached input tokens. OpenAI docs state promotional pricing available at least through November 21, 2026. Prompts over 272K input tokens are priced at 2x input and 1.5x output.
OpenAI's original GPT-5.6 preview announcement describes Sol as the flagship preview, and current OpenAI API documentation gives token rates for the corresponding generally available GPT-5.6 Sol model. The documentation does not list a separate current SKU called “GPT-5.6 Preview”; this finding uses Sol's current public rate as the closest documented match. The model accepts text and image input and outputs text.