GPT-6.1 Sol

GPT-6.1 Sol is an OpenAI model launched at DevDay on September 29, 2026, positioned as a cost-focused refresh that lands one week after GPT-6 Sol and roughly a month after GPT-6 Astra. OpenAI describes it as an upgrade to GPT-6 Sol that nearly matches Astra's performance on agentic coding, computer use, and multi-step professional work while charging only about a fifth of Astra's standard token rates. That positioning reflects a deliberate middle tier in the GPT-6 lineup: more capable than the entry-level Luna variant, but engineered for everyday workloads where Astra's premium pricing had become a barrier.

In practical benchmark terms, GPT-6.1 Sol matches GPT-6 Astra on the DeepSWE v1.1 software-engineering suite at substantially lower cost, while eclipsing GPT-6 Sol's previous DeepSWE best score by 6.4 points at a reduced reasoning effort. It also edges past Anthropic's Claude Opus 5.5 by about 2.2 points on AutomationBench at medium effort, and runs Terminal-Bench Science 0.1 tasks at roughly $5.47 each versus Astra's $23.80, according to OpenAI's published figures. The combination of a roughly 1,050,000-token that quick-info value window, a 128,000-token maximum output, and aggressively discounted cached input pricing makes the model a practical fit for long-running agentic pipelines, repeated document analysis, and multi-turn coding sessions that benefit from reuse of prior turns.