GPT‑5.3‑Codex‑Spark

GPT-6.1 Sol is an OpenAI model designed to deliver near-GPT-6 Astra intelligence at substantially lower cost across coding, professional work, computer use, scientific research, and agentic workflows. It improves on GPT-6 Sol across complex tasks such as software engineering, document analysis, multi-step business automation, and computer interaction. On DeepSWE v1.1, GPT-6.1 Sol matches GPT-6 Astra at roughly one-fifth of the cost while exceeding GPT-6 Sol's best score by 6.4 percentage points at a lower reasoning effort. The model also improves computer use, outperforming GPT-6 Sol by seven percentage points on the OSWorld 2.0 offline set at maximum reasoning effort while costing less than half as much per task. GPT-6.1 Sol provides improved factuality and alignment, including greater transparency about limitations and stronger adherence to user instructions during agentic tasks. It is available through ChatGPT Work, Codex, and the OpenAI API.

GPT-6 Luna is OpenAI’s cost-efficient GPT-6 model designed for everyday professional work, coding, computer use, and agentic applications at scale. It brings many of the advances introduced with GPT-6 Astra to a faster and substantially lower-cost model while improving on GPT-5.6 Luna in capability and factual reliability. The model supports adjustable reasoning effort, allowing applications to spend more compute on harder tasks and less on simpler requests. GPT-6 Luna can handle software engineering, multi-step business workflows, computer interaction, and other tool-using tasks that benefit from low operating cost. Improved GPT-6 prompt caching helps long-running agents reuse more context, respond faster, and reduce the cost of repeated input. GPT-6 Luna is available in ChatGPT Work, Codex, the ChatGPT desktop app for Free and Go users, and the OpenAI API as gpt-6-luna.