Nicovideo Autoplay Canceler is a Chrome extension designed to enhance the user experience on the Nicovideo platform by automatically pausing videos that start playing without user interaction. This tool addresses the recent changes to the Nicovideo interface that trigger auto-play upon opening a video page. The extension detects the auto-play event and pauses the video shortly after it begins, providing users with greater control over their viewing experience.

One notable feature of this extension is its ability to rewind the video to the beginning if the playback time is less than three seconds at the moment of pausing. However, if the user has the resume playback feature enabled and the video has played for more than three seconds, the playback time will not be reset. This functionality ensures that users can manage their viewing preferences with minimal interruption.