OpenAI rolls out GPT-5.1 to refine ChatGPT with adaptive reasoning and personalization

OpenAI has introduced GPT-5.1, an update to its GPT-5 model, aiming to deliver faster responses, improved reasoning, and more flexible conversational controls as the company works to refine its ChatGPT experience for both consumer and enterprise users.The release includes new Instant and Thinking variants designed to offer more adaptive reasoning and a broader range of personalization options, the company said in a blog post.

GPT-5.1 is available across ChatGPT’s free and paid tiers, with enterprise and education customers receiving a brief early-access period before it becomes the default model. OpenAI said the models are also accessible through the API.

In a separate Substack post, OpenAI CEO for Applications, Fidji Simo, said these chat models are “trained using the same stack as our reasoning models,” adding that they “score higher on factuality and complex problem-solving than GPT-5, while also introducing a more natural, conversational tone.”

The update expands ChatGPT’s personalization controls with presets such as professional, friendly, candid, quirky, efficient, cynical, and nerdy, and aims to improve the reliability of custom instructions so they persist across multi-turn conversations.

Implications for enterprises

Analysts point out that the real story with GPT-5.1 is not the headline features but the subtle behavioral shifts that remove a lot of the friction enterprises quietly learned to live with this past year.

“The model is quicker to pick up intent, less likely to wander, and noticeably better at keeping a steady voice from one message to the next,” said Sanchit Vir Gogia, chief analyst, founder, and CEO of Greyhound Research. “That alone cuts a surprising amount of hidden operational waste. Teams no longer need to rephrase the same request four different ways or spend half their time smoothing out tone inconsistencies that creep into customer-facing text. This is something CIOs would appreciate.”

The real test is whether it reduces manual clean-up. Enterprises want fewer correction cycles and escalations. They also want a model that does not start acting like a different personality mid-conversation.

“GPT-5.1 makes progress on all of that,” Gogia said. “Coding output is steadier, long-context reasoning is less fragile, and the model is less prone to slipping into verbose rambling or over-polite filler. You can feel the engineering underneath. The routing architecture and the dual-style reasoning pathways matter more than the marketing language around them.”

However, it may be challenging for CIOs to fully evaluate GPT-5.1’s improvements, as many changes focus on enhancing user experience through better tonality and reasoning, according to Anushree Verma, senior director analyst at Gartner.

“These updates increase the model’s immersive capabilities, capturing users’ attention and encouraging stronger engagement,” Verma added. “Other models have positioned tonality as a competitive differentiator, and GPT-5.1’s upgrades have been made with this in mind.”

OpenAI’s competitive position

The update comes as OpenAI faces stiff competition from rivals, including those in China, and after ChatGPT 5 faced criticism for issues during rollout.

“The shine of being the default choice has faded,” Gogia said. “Enterprises that once embraced OpenAI without hesitation are now mixing and matching models to suit workload, cost, and regulatory expectations. GPT-5.1 helps OpenAI reassert itself not by leaping ahead on raw capability, but by focusing on the fundamentals that shape enterprise confidence.”

But rivals like Claude, Gemini, Mistral, and emerging open-source models are vying for market share, and modern enterprise architectures increasingly assume a multi-model fabric as the norm.“In such a situation, GPT-5.1 functions less as a single pillar and more as the strongest member of a larger toolkit,” Gogia said. “It will still be the preferred choice for deep analytical work and ambiguous, multi-step tasks, but it must now coexist with competitors that outperform it in cost-sensitive or domain-specific scenarios.”