UDL Helper is a robust YouTube downloader that simplifies MP3 and MP4 downloads with one click. It supports high-quality video and audio downloads, including from Instagram and Odnoklassniki. The extension maintains original file names, offers a choice of button styles, and even supports 'embedded' videos from third-party sites. Users can extract MP3 audio from online videos, and the extension also facilitates screenshot capture. It's a comprehensive tool with a sleek design, a user-friendly interface, and useful settings.