Yuhappy is a free Chrome add-on designed to enhance vocabulary acquisition while browsing the web. This tool extracts and highlights vocabulary words from any webpage, allowing users to focus on words that require attention. It supports a comprehensive vocabulary book system tailored for various educational levels, including Grade 4 to 6, IELTS, and TOEFL. Key features include word dictation, intelligent error hints, and anti-forgotten algorithms that help reinforce memory retention through regular review.

The application emphasizes personalized learning by matching vocabulary highlighting and translations based on selected vocabulary books and difficulty levels. Users can read content that interests them while building and training their vocabulary books. Additionally, Yuhappy integrates dictation of words, phrases, and example sentences to promote efficient memory, utilizing visual aids and audio to enhance understanding and retention of vocabulary.