Arctic Shift is an open-source archive of historical Reddit posts and comments, maintained independently by Arthur Heitmann. It provides bulk data dumps, a public API and a search interface, with no key and no registration.
Subdex uses its API. Your browser contacts it directly — the query never passes through a Subdex server, because there isn't one.
What it covers
Historical posts and comments across Reddit, going back well before the archive itself existed, assembled from earlier collection efforts and ongoing capture.
It is not a live mirror. The archive lags Reddit, so recent activity may be absent.
Two limits worth knowing
Scores settle slowly. Records are captured when posted and updated later. For roughly the first 36 hours, score and comment count carry placeholder values rather than real ones. Subdex excludes those records from score statistics and reports how many it excluded.
Keyword search is constrained. Keyword parameters only work alongside an author, subreddit or thread. There is no way to search all of Reddit for a word.
It is a free service
Run by one person, with no uptime guarantee. Subdex caps itself at two concurrent requests and backs off when asked to. For bulk work, the published data dumps are the right tool rather than the API.