Find Similar Subreddits

Type any subreddit name and instantly see a graph of communities that share the same audience — based on real user overlap data across millions of Reddit profiles.

Direct neighbors

    How to Use the Similar Subreddits Tool

    Five quick steps — each card is one interaction loop you can skim top-to-bottom.

    1. Search a subreddit

      Enter a name without the r/ prefix. Press Enter or tap Find. Any community in the public similarity dataset works — tens of thousands of active subs are covered.

    2. Read the graph

      • Center — the subreddit you searched.
      • Dots — neighboring communities by overlap.
      • Lines — similarity relationships (edges).
      • Distance — closer usually means stronger shared audience.

      Layout is force-directed: highly linked subs drift inward; weaker ties drift outward.

    3. Explore nodes

      • Single-click — preview on the side; jump to Reddit or recenter from the panel.
      • Double-click — rebuild the graph around that subreddit.
    4. Move around the canvas

      • Zoom — scroll wheel or pinch.
      • Pan — drag empty space.
      • Controls — corner buttons for precise zoom.
      • Fit — resets so every node is visible.
    5. Optional: deeper hops

      Default depth is two rings from your starting subreddit. Append ?maxDepth=3 to the URL when you want a wider fringe (more distant cousins on the interest graph).

    Why Find Similar Subreddits?

    Community Discovery

    Reddit has millions of active communities. No search box can surface them all. The similarity graph reveals communities that share your interests but that you'd never think to search for by name — the "unknown unknowns" of the Reddit ecosystem.

    Content Strategy & Cross-Posting

    If you create content for Reddit, knowing which subreddits share an audience tells you where your posts have the highest chance of resonating. Communities that appear as direct neighbors in the graph have the most user overlap — meaning the same people are likely reading both.

    Research & Analysis

    Academics, journalists, and data analysts use subreddit similarity graphs to map the topology of online communities — understanding which interest clusters sit adjacent to each other, how niche communities relate to mainstream ones, and how information might travel between groups.

    Moderation & Community Building

    Subreddit moderators use similarity data to find partner communities for cross-promotion, rule alignment, and coordinated event hosting. Seeing your community's neighborhood in the graph makes partner selection data-driven rather than guesswork.

    About the Data

    This tool is built on subreddit similarity data originally computed and published by developer Andrei Kashcha as part of his open-source sayit project. The similarity score between two subreddits is derived from user overlap — the proportion of users who are active in both communities relative to the total user base of each.

    A high similarity score means many of the same people participate in both subreddits. This is a behavioral signal — it reflects what users actually do, not how subreddits are tagged or described. As a result, the graph sometimes reveals surprising connections: communities that seem unrelated by topic but share a distinct, overlapping audience.

    The dataset covers tens of thousands of subreddits with sufficient activity to compute meaningful similarity scores. Very small or very new communities may not appear in the results. Technical background lives in the legacy sayit repository. For methodology in plain language, see how to use this page.

    Browse by starter category

    Each pill opens a dedicated similarity landing page — useful when you want a themed tour instead of guessing keywords.

    Popular Subreddits to Explore

    Next: Map of Reddit

    Want to see every major community at once? The interactive galaxy maps more than 116,000 subreddits — position still reflects overlap, just at continental scale.

    Open Map of Reddit →

    Frequently Asked Questions

    How do I find subreddits similar to one I already use?
    Type the subreddit name in the search box above (no r/ needed) and press Enter. The graph shows similar communities immediately.
    What does "similar subreddits by user overlap" mean?
    It means the similarity score is based on how many of the same users are active in both communities — not on topic tags or descriptions. If many of r/A's users also post in r/B, those subreddits have high overlap.
    Is this the same as anvaka's sayit tool?
    Yes — this tool uses the same underlying dataset and algorithm as anvaka.github.io/sayit, with an updated interface.
    Why isn't my subreddit showing up?
    Small or inactive subreddits may not have enough user data to compute similarity scores. The dataset covers communities above a minimum activity threshold.
    How is this different from Reddit's built-in recommendations?
    Reddit recommendations mix signals including moderation and taxonomy. This tool highlights behavioral overlap from historic comment activity — often surfacing less obvious but genuinely adjacent communities.
    Can I see similar subreddits for NSFW communities?
    The dataset includes a broad range of communities. Results depend on what is present in anvaka public similarity data.
    How often is the data updated?
    The similarity dataset is a static snapshot computed by anvaka. It reflects Reddit community structure at the time of data collection.

    Source code: github.com/anvaka/sayit ↗

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