With the Korean webtoon gaining popularity around the world, the webtoon ecosystem for more convenient producing, exposing, and distributing of contents is created by platform companies. This study investigates the nature and implications of fan translation carried out on WEBTOON and Torycomics, online webtoon platforms, focusing on technical assistance provided by platform companies, rewards for fan translators, evaluation of fan translation, and utilization of language data. Literary review and an interview with Bae Soo Ho, CEO of Torycomics, revealed that platform companies create a transnational stage for fans by setting translation guidelines and rules, monitoring fan activities and providing technical assistance so that fans can easily complete translation and share their favorite cultural contents. The translation process is user-friendly with nothing needs to be installed: fans get access to original contents on companies’ websites or mobile apps, use upgraded tools provided online to translate and upload their translation, which will instantly shared with webtoon fans around the world. The webtoon-specific language data is built up with categories for onomatopoeia, culture-specific words, and slang. The database creates revenues for companies by being channeled into online dictionaries and machine translators or sold to other companies.