Bunsho Kosei AI is a free web-based proofreading tool from User Local, Inc. that integrates with ChatGPT for context-aware Japanese text correction. The tool detects particle misuse, typos, character omissions, colloquial expressions like ra-nuki, and inappropriate word choices, presenting correction suggestions for each issue.
Beyond error detection, the service offers writing style conversion between dearu-style (plain form, common in academic writing) and desu-masu-style (polite form, standard for business documents). Users can let the AI select the appropriate style automatically or specify their preference.
User Local has operated in the Big Data and AI space since 2007, bringing accumulated expertise to this free tool. The service requires no registration and has no payment tiers, making it accessible for anyone needing quick Japanese text proofreading for business documents, articles, or everyday writing.