Wrtn Scales Lifestyle AI to 6.5M Users with GPT-5 in Korea

Wrtn, a Korean AI company, has successfully scaled its Lifestyle AI to 6.5 million users in Korea using GPT-5, OpenAI's latest model. The company's innovative approach to integrating AI into daily life has led to significant user growth and engagement, particularly within Korea’s character-driven digital culture.

Expansion of AI Productivity Tools

Wrtn initially focused on individual productivity with AI-powered writing assistants and note-taking tools. However, their vision evolved to create a 'Lifestyle AI' that seamlessly integrates into users' daily routines. This shift has resulted in a diverse product suite, including AI Supporter, Labs, and Crack, which have seen doubled retention rates and quadrupled time spent per user.

Localization and User Engagement

One key challenge was nuanced localization for the Korean market. With GPT-4 and GPT-4.1, Wrtn improved the AI's tone to incorporate slang, humor, and internet expressions. The company further enhanced human-like responses through system prompt injections, persona-based role guidance, and temperature tuning.

Technical Architecture

Wrtn employs a router architecture, directing traffic with lightweight models like GPT-4o mini and GPT-4.1 mini, while heavier tasks use GPT-4.1 and multimodal TTS. The launch of GPT-5 led to an immediate 8% increase in daily active users within a week, attributed to improved instruction adherence, context handling, and personalization.

Impact and Future Plans

Wrtn’s success demonstrates how advanced AI models can be made accessible and useful for millions in learning, creativity, and communication. The company is now planning to expand its model across East Asia, building on its strong foundation in the Korean market.