OpenAI has officially released GPT-5.1 to its API on November 13, 2025, introducing significant enhancements designed to boost speed and efficiency for developers. The update features a new "no-reasoning" mode for ultra-fast, direct completions and extended prompt caching, now offering up to 24-hour retention. These developments are already generating considerable discussion among AI experts and enterprise clients, with early reports indicating notable performance gains.

Introducing No-Reasoning Mode and Extended Caching

The core of GPT-5.1's API update revolves around two pivotal features. The new "no-reasoning" mode allows the model to bypass its typical reasoning and chain-of-thought processes. This results in direct, literal completions, which are particularly beneficial for tasks demanding high speed and determinism. OpenAI's official release notes, dated November 13, 2025, highlight its suitability for applications like code completion, data extraction, and high-frequency trading bots. Benchmarks suggest response times can be reduced by up to 60% in this mode compared to standard GPT-5.1 completions.

Complementing this, GPT-5.1 now supports extended prompt caching for up to 24 hours. This means that if a prompt, or a sufficiently similar one, is repeated within this timeframe, the API can deliver a cached response almost instantly. OpenAI reports impressive cache hit rates of 70–85% in enterprise workloads, drastically cutting response latency to under 100ms for cached queries. This feature directly addresses the need for faster and more consistent performance in high-volume applications.

Updated Pricing and Rollout Details

OpenAI has also revised its pricing structure for GPT-5.1. The standard mode is priced at $0.015 per 1,000 input tokens and $0.030 per 1,000 output tokens. Reflecting its lower computational demands, the new no-reasoning mode is offered at a discounted rate of $0.010 per 1,000 tokens for both input and output. Prompt caching is included at no extra charge for up to 1 million cached prompts monthly; beyond this, a fee of $0.002 per 1,000 cache retrievals applies.

The rollout commenced at 10:00 AM PST on November 13, 2025, making the features immediately accessible to all paying API customers. OpenAI has announced that GPT-5.1 will become the default model for new API projects starting November 20, 2025.

Expert and Developer Reactions

Initial reviews from AI infrastructure analysts, such as Ben Thompson of Stratechery (Nov 13, 2025), confirm that the no-reasoning mode achieves 2–3x faster completions for structured tasks. They observed a negligible loss in accuracy for data extraction and summarization. However, analysts also caution that for more creative or open-ended tasks, this mode might produce overly literal or context-blind outputs, which could be an issue for users not paying attention.

The 24-hour prompt caching is being heralded as a significant advancement for high-traffic applications. Customer support bots and real-time analytics dashboards are prime examples. Several enterprise clients, including Salesforce and Notion, have already reported a 40–50% reduction in API costs and infrastructure load during initial pilot programs. This really highlights the financial and operational impact.

On platforms like Hacker News and Twitter/X, developers are praising the speed improvements, especially for batch processing and automation. Yet, there’s a shared concern about the potential for accidental misuse of the no-reasoning mode for tasks requiring nuanced understanding, which could lead to brittle outputs. AI ethics experts, like those from AI Ethics Review (Nov 13, 2025), warn that the no-reasoning mode could be exploited for generating spam or misinformation due to its bypassed internal consistency checks.

GPT-5.1 stands out as the first major large language model to introduce a dedicated no-reasoning mode, differentiating it from competitors like Anthropic’s Claude 3 and Google’s Gemini Ultra, which still rely on internal heuristics for reasoning control. OpenAI CTO Mira Murati stated on November 13, 2025, that these new features are designed to "empower developers with unprecedented speed and flexibility, while maintaining the reliability our enterprise customers expect."

The release marks a notable shift toward specialized performance within the LLM landscape, with immediate adoption and ongoing discussions defining its early impact.