OpenAI cuts GPT-6 Sol and Luna API prices by 50%

OpenAI launched updated versions of its GPT-6 Sol and Luna models on Tuesday, cutting API prices to half or less what developers paid for the previous 5.6 series — a reduction the company says is permanent rather than promotional.

GPT-6 Sol is priced at $2 per million input tokens and $10 per million output tokens, down from $4 and $20 respectively for GPT-5.6 Sol. GPT-6 Luna comes in at $0.10 per million input tokens and $0.50 per million output tokens, down from $0.20 and $1.20, according to VentureBeat. An OpenAI spokesperson confirmed to VentureBeat that the new rates carry no expiration date.

OpenAI attributed the price reductions to improvements in caching and inference. The company says GPT-6 Sol makes roughly half as many factual errors as its predecessor and is approaching the reliability of GPT-6 Astra, the flagship model released earlier this month, at a lower cost.

Sol targets developers and knowledge workers who need a capable model for demanding, repeatable jobs — writing and reviewing code, building software features and working through large datasets. Luna is meant to handle large quantities of routine work where the objective is narrow and predictable — pulling out information, condensing documents or fielding simple queries — according to TechCrunch. GPT-6 Astra remains available for the most demanding tasks.