OpenAI has recently rolled out GPT-5.1, an incremental yet significant upgrade to its flagship large language model series, making it available to ChatGPT users and developers alike. Launched on November 12-13, 2025, this update introduces enhanced conversational capabilities, adaptive reasoning, and new customization features, alongside powerful tools for developers. For businesses, GPT-5.1 promises to elevate efficiency, improve user interactions, and streamline complex agentic and coding workflows.
Key enhancements in GPT-5.1
The GPT-5.1 release focuses on two primary models: GPT-5.1 Instant and GPT-5.1 Thinking, each receiving distinct improvements. GPT-5.1 Instant, the most frequently used model, is now notably warmer, more intelligent, and demonstrates superior instruction following. It also features adaptive reasoning, allowing it to “think before responding” to challenging questions, leading to more thorough and accurate answers while maintaining speed.
GPT-5.1 Thinking, designed for advanced reasoning, has been optimized for efficiency and clarity. It dynamically adjusts its thinking time, spending more effort on complex problems and responding faster to simpler ones. Its responses are clearer, with reduced jargon, making it more accessible for intricate business tasks and technical explanations.
Enhanced customization and new developer tools
A significant user-facing update in ChatGPT is the expanded personalization settings. Users can now tailor ChatGPT’s tone and style with new presets like Professional, Candid, and Quirky, alongside updated Friendly and Efficient options. For more granular control, OpenAI is experimenting with direct tuning of characteristics such as conciseness, warmth, or emoji frequency. These preferences now apply instantly across all ongoing chats, ensuring a consistent user experience.
For developers, GPT-5.1 in the API brings several critical advancements:
- Efficient Reasoning: The model dynamically adjusts thinking time, leading to faster responses and lower token costs on simpler tasks, while maintaining persistence on complex ones.
- “No Reasoning” Mode: Developers can now set
reasoning_effortto ‘none’ for latency-sensitive applications, achieving high intelligence with faster performance for tasks that don’t require deep thinking. - Extended Prompt Caching: Prompts can remain active in the cache for up to 24 hours (previously minutes), reducing latency and cost for long-running interactions.
- Improved Coding: GPT-5.1 offers a more steerable coding personality, less overthinking, better code quality, and more functional frontend designs. Benchmarks like SWE-bench Verified show an increase to 76.3% accuracy.
- New Tools:
apply_patch: A freeform tool to reliably edit code using structured diffs, enabling iterative, multi-step code editing workflows.shell: A tool that allows the model to propose and execute shell commands on a local machine, creating a powerful plan-execute loop for system inspection and data gathering.
Business impact and availability
The GPT-5.1 update is particularly impactful for businesses seeking to deploy more intelligent, efficient, and customizable AI solutions. The adaptive reasoning and improved coding capabilities are poised to enhance developer productivity significantly, enabling the creation of more robust agentic workflows. The extended prompt caching offers cost savings and smoother performance for multi-turn chats and complex knowledge retrieval systems.
GPT-5.1 Instant and Thinking are rolling out to paid ChatGPT users (Pro, Plus, Go, Business) starting November 12-13, 2025, with free and logged-out users gaining access subsequently. Enterprise and Edu plans have a seven-day early-access toggle. Both GPT-5.1 Instant (as gpt-5.1-chat-latest) and GPT-5.1 Thinking (as GPT-5.1) are available in the API, with pricing and rate limits consistent with GPT-5. Additionally, gpt-5.1-codex and gpt-5.1-codex-mini models are released for specialized agentic coding tasks. GPT-5 will remain available as a legacy model for three months to facilitate a smooth transition.
