# Reddit Atlas

> A year-by-year map of Reddit communities from 2006 through 2025, organized by shared user participation rather than the words people posted.

Canonical URL: https://reddit-atlas.fly.dev/
Creator: [Ansh Sancheti](https://anshsancheti.github.io/)
Status: Public interactive data project

## What it is

Reddit Atlas turns public Reddit activity into a navigable history of the site's communities. Its yearly source aggregates cover 24.88 billion posts and comments.

The map does not use titles, comments, post bodies, or text embeddings to decide which communities are related. Two subreddits are connected when many of the same non-filtered accounts participated in both during a year. Prolific authors are downweighted so they do not dominate the graph. Node size reflects active authors, and color reflects graph-derived community clusters.

Each annual map is a two-dimensional layout of a participation graph. It is useful for exploring local relationships, not as a precise global distance metric. The selected community's neighbor list and shared-author counts are the direct evidence of similarity.

## What visitors can do

- Explore yearly maps from 2006 through 2025.
- Search for a subreddit and inspect its size, cluster, and strongest participation neighbors.
- Share stable year-and-community URLs such as `/2025/r/AskReddit`.
- Read the methodology and yearly quality-assurance reports.

## Important links

- [Open Reddit Atlas](https://reddit-atlas.fly.dev/)
- [Read the methodology](https://reddit-atlas.fly.dev/methodology.html)
- [More work by Ansh Sancheti](https://anshsancheti.github.io/)