OpenAI announced Thursday it is reducing the price of two models in its GPT-5.6 family — cutting the cost of GPT-5.6 Luna by 80% and GPT-5.6 Terra by 20% — roughly three weeks after the models launched, according to CNBC.
Luna, the fastest and lowest-cost version in the GPT-5.6 lineup, is now priced at 20 cents per million input tokens and $1.20 per million output tokens, a reduction from its previous rates of $1 and $6
Terra, the mid-tier model, will see its input token rate fall to $2 per million and output token rate fall to $12 per million, compared with the prior $2.50 and $15. The pricing for Sol, the most powerful model in the family, remains unchanged, the company said. OpenAI attributed the reductions to efficiency gains made during internal development of GPT-5.6, including the model’s ability to rewrite and optimize production code and improve token generation, the company said.
Those improvements reduced the end-to-end cost of serving the model by 20% and increased token-generation efficiency by more than 15%. The cuts arrive as enterprise customers have grown reluctant to authorize large AI expenditures without a clear picture of returns, according to Reuters. Cheaper Chinese open-weight models have sharpened the competitive environment, pushing OpenAI and rival Anthropic to make the case that their products are worth the premium, according to Axios.