Pinyin Annotator is a Chrome browser extension designed by fixicelo to enhance the online Chinese learning experience. This tool seamlessly overlays Hanyu Pinyin annotations on Chinese characters found on web pages and video subtitles, making it a valuable resource for individuals studying the Chinese language.

The key features of Pinyin Annotator include integrating pinyin into Chinese subtitles on popular video streaming platforms like Netflix, Disney+, YouTube, and Bilibili. Additionally, it supports both Simplified (汉) and Traditional (漢) Chinese, offers easy accessibility by allowing users to view pinyin of selected text with a simple click, and is open-source, enabling users to review and contribute to its code on GitHub.