SubRedds is a web based tool that provides a searchable directory of over 100,000 active Reddit communities, organized by size and activity. Its primary function is to allow users to browse, filter, and explore subreddits based on metrics such as community size and posting frequency. The platform also functions as an archival viewer: it displays every image and video ever posted to a given subreddit in a single grid of thumbnails, going back to the beginning of that community. Similarly, it can aggregate all posts made by a single user across every subreddit onto one page, preserving content even after the original poster has deleted it. Key features include the ability to create custom categories and drag subreddits between them, with each category functioning as a dedicated feed of its constituent subreddits. Users can import new subreddits by entering the name, the r/name format, or the full subreddit URL. The platform also offers a saved content summary, a feed view for user defined groups of subreddits, and a restore function for subreddits that were initially loaded upon sign up. A free account adds the ability to save subreddits and organize them into categories. Typical use cases involve discovering new subreddits by size or activity, browsing the complete visual history of a community, tracking a user’s entire posting history, and curating personalized feeds for different moods or topics. The workflow starts with a search or browse action, then allows users to save and organize subreddits into custom categories, which can be viewed as aggregated streams. The site stores user information as described in its privacy policy, and users agree to its terms and conditions when creating an account. SubRedds is accessible at subredds.com and requires no special technical setup beyond a standard web browser.