OpenAI Unveils GPT-5.1 in Seoul: Adaptive Reasoning, Personalized Tone and a Full Suite of Next-Gen Upgrades

At its first-ever developer event in Korea, OpenAI introduced the latest evolution of its GPT-5 family—GPT-5.1 Instant and GPT-5.1 Thinking—during the OpenAI DevDay Exchange Seoul held on November 13. The event marks a significant moment for the company, which opened its Seoul office as its third branch in Asia, following Tokyo and Singapore.

By showcasing core updates directly to more than 150 leaders in Korea’s ICT sector, OpenAI signaled its intention to deepen relationships with local enterprises and strengthen its foothold in the Korean B2B market.

Seoul Hosts Its First OpenAI DevDay: A Clear Push Toward a Korea-Focused Strategy

Held in Mapo, the Seoul DevDay Exchange brought together industry insiders for an exclusive look at OpenAI’s upgraded model lineup.

By delivering key announcements from the U.S. DevDay on Korean soil, the company highlighted Seoul’s rising status as a strategic hub in Asia. The event also emphasized OpenAI’s commitment to tailoring its technology roadmap for Korean businesses and developers.

Inside GPT-5.1: Adaptive Reasoning Balances Speed and Accuracy

The central focus of the announcement was GPT-5.1 Instant, which introduces a new capability OpenAI calls Adaptive Reasoning.

This system enables the model to evaluate the complexity of a question on its own—responding instantly to simple prompts while taking more time to think through harder problems. The result, OpenAI says, is an AI that performs fluidly across everyday queries, enterprise workflows, and high-stakes decision-making scenarios, achieving a new equilibrium between speed and accuracy.

GPT-5.1 Thinking: Deeper Logic for Complex Problems

For more advanced tasks, OpenAI unveiled GPT-5.1 Thinking, a higher-tier model designed to extend reasoning depth based on user intent and problem difficulty.

The model allocates more structured “thinking time” when tackling nuanced tasks such as strategy planning, technical architecture reviews, or policy and legal interpretation—areas where reliability and logical consistency are critical.

OpenAI also emphasized improvements in clarity, reducing jargon and ambiguous phrasing to ensure responses remain widely accessible, especially for enterprise users.

Six New Tone Options: Toward a More Personalized ChatGPT

One of the most notable user-facing upgrades is the expansion of ChatGPT’s customizable communication styles.

In addition to the previous “Default,” “Friendly,” and “Efficient” tones, three new styles—Professional, Direct, and Quirky—have been added.

This opens opportunities for companies to align ChatGPT outputs with brand identity, customer-facing standards, training content, and marketing voice. OpenAI says the goal is to support both individual preferences and official corporate communication needs.

Building Bridges with Korean Enterprises as B2B Strategy Accelerates

Beyond the technical reveal, OpenAI placed heavy emphasis on networking with Korean firms.

A company representative said OpenAI plans to expand its support infrastructure so local businesses can actively integrate GPT-5.1 features into their products and services.

The decision to host DevDay in Korea—immediately after establishing its Seoul office—reflects the country’s growing strategic importance in OpenAI’s Asia roadmap, and signals a broader ambition to accelerate growth in the domestic B2B market.

By Song-ah Choiㅣchoesonga627@gmail.com