Reddit Au Comment Highlights is a Firefox add-on designed to enhance the user experience on Reddit by providing comment highlights, a feature typically reserved for Reddit Gold users. This lightweight extension offers a customizable interface that allows users to tailor their experience according to their preferences. It requires minimal permissions, ensuring user privacy while enabling seamless synchronization between browser sessions for ease of use.

One of the notable features of this add-on is its compatibility with the Reddit Enhancement Suite (RES) night mode and the ability to apply custom CSS, allowing users to personalize their Reddit browsing further. However, it is important to note that comment highlights will only appear after the second visit to a comment thread following installation, making it essential for users to interact with the feature to fully utilize its capabilities.