*This is the first instalment of Swipe, a regular column in which we open up and examine AI apps and services making waves in Korea. First under the microscope: Wrtn, the country's leading generative AI platform.*

Introduction

Wrtn is a Korean AI platform developed by Wrtn Technologies. Its name blends "Writing" and "AI" — a fitting description of its original ambition. When the company launched Wrtn 2.0 in January 2023, it became one of the earliest consumer-facing generative AI services in Korea. The firm is led by Lee Yong-jin, born in 1996, and has since expanded its product range to include AI Supporter, Labs, and Crack.

Core Features

Wrtn's central proposition is straightforward: access multiple AI models through a single app. Users can switch between GPT-4o, GPT-4.5, o1, Claude 3.7, Gemini 2.5, and other leading large language models depending on the task at hand. The platform claims to automatically determine whether a query requires a live internet search, routing it accordingly — without the user having to configure anything. It also offers more than 20 specialised tools for work and study, all available free of charge with no usage limits, as well as document and image analysis.

The more technically interesting feature is Wrtn's proprietary router architecture. A lightweight model — GPT-4o mini — first classifies and distributes incoming traffic, while heavier tasks such as tutoring or counselling are handled by GPT-4.1 and a multimodal text-to-speech system. According to a case study published by OpenAI, the introduction of this router increased average session length by 15% and improved first-month retention by 10%. Within a month of adding the audio model, users had generated over 10,000 hours of tutoring conversations. The company says it now has 6.5 million monthly active users.

The product is also growing more playful. Wrtn has added AI-generated horoscopes and fortune reports, trending meme generators, and integration with KakaoTalk — South Korea's dominant messaging app, analogous to WhatsApp in much of Europe. A separate business unit, Wrtn AX, targets enterprises and public institutions. It has already won contracts to build an AI press-release drafting tool for the Ministry of Culture, Sports and Tourism, and a generative AI platform for the Gyeonggi Provincial Office of Education, establishing a foothold in the government procurement market.

Strengths and Limitations

Wrtn's clearest advantage is its Korean-language optimisation. Rather than simply routing queries through foreign models, the company has invested noticeably in capturing the nuances of Korean conversation and cultural context. The ability to access multiple state-of-the-art models for free, all within one interface, is another genuine selling point for cost-conscious users.

There are weaknesses, however. Between December last year and January this year, users reported that the AI's conversational tone changed abruptly — a problem that appears not to have been fully resolved at the time of writing. Some users have also noted that the document-summarisation feature occasionally fails on the first attempt, requiring a retry before working correctly.

Perhaps the most revealing observation is that Wrtn's primary revenue driver is not its chatbot service at all, but Crack — a character chat app run by the same company. Crack allows users to converse with fictional characters and quickly became one of Korea's top-grossing chat applications after launch. That success signals something important: the product that has resonated most strongly with paying users is not a productivity tool, but an entertainment one. The two are quite different businesses.

Verdict

Wrtn offers a useful snapshot of how far Korean AI services have come. Its effort to integrate and localise multiple foreign models for Korean speakers is substantive, and 6.5 million monthly active users is no small achievement. Yet the fact that a character-chat entertainment app is outperforming the productivity platform that originally defined the brand raises a genuine strategic question: which identity will Wrtn choose to build on?

★★★☆☆ (3.5/5.0)

In a sentence: "It bet on the Korean language — and then found its biggest hit somewhere else entirely."