Fude (筆) is an AI-powered Chrome extension designed to assist users in writing correct Japanese, particularly focusing on grammar and keigo. With its unique three-level keigo system, it caters to various contexts, from casual conversations to ultra-formal business communications. The extension provides real-time corrections for grammar mistakes, particle errors, and mismatched keigo levels, making it a valuable tool for JLPT learners and professionals alike. It supports multiple platforms, including Gmail, Slack, and Google Docs, ensuring users can write accurately across different applications.

The tool is especially beneficial for those preparing for Japanese Language Proficiency Tests (JLPT), as it offers corrections along with their corresponding JLPT levels. Fude also includes furigana readings for better understanding. While the free version allows for ten corrections per day, the Pro version unlocks unlimited corrections and additional features for a monthly fee. Fude prioritizes user privacy by ensuring that texts are processed securely without permanent storage.