ReddGraph

Every subreddit shares some of its people with other subreddits. This map draws the 250 subreddits that the most people in my sample were active in, and pulls together the ones that share more people than their sizes alone would predict. Hover or tap one to see where its people also go.

To build it, I sampled 20 commenters from each of Reddit's 100 largest safe-for-work subreddits, then looked up every subreddit each of them posted or commented in at least twice from June to August 2026. That is 2,000 people. The page only has the totals: no usernames. This is a proof of concept for a larger map.

Limitations

Activity, not subscriptions. Reddit does not publish who subscribes to what, so this counts where people post and comment. Someone who only reads never shows up.
Seen from the big subreddits. Everyone in the sample was found commenting in one of the 100 largest subreddits, and people who comment a lot were likelier to be picked. Smaller communities only appear when enough of those people go there.
A sample, not a census. 2,000 people is enough to see the shape, not to trust every line. A link needs at least 5 shared people, so weak ties are missing, and some strong-looking ones rest on a handful of people.
Links are measured against chance. A link's strength is its overlap relative to both subreddits' sizes, so general subreddits that everyone passes through do not link to everything.
Filtered. NSFW subreddits, bots and user profile pages are left out.

Data: the Arctic Shift archive of Reddit. The layout (ForceAtlas2) and the communities (Louvain) are computed ahead of time with networkx; the page only draws them. The scripts are in tools/reddit-map/.