What are the limitations and rate limits of Reddit's API?

Reddit's Data API is available to developers building applications, bots, and research tools, but it operates under a specific set of rate limits and access restrictions that became significantly stricter after Reddit restructured its API pricing policy in mid-2023. The free tier of the API allows 100 queries per minute (QPM) per OAuth client ID when authenticating with OAuth, averaged over a rolling 10-minute window. For unauthenticated access — making requests without OAuth credentials — the limit drops to 10 queries per minute. Reddit enforces these limits through response headers: `X-Ratelimit-Used`, `X-Ratelimit-Remaining`, and `X-Ratelimit-Reset` indicate how many requests have been made in the current period, how many remain, and how many seconds until the window resets. Applications that exceed the rate limit receive a 429 status code response and should implement exponential backoff — progressively longer delays between retry attempts — rather than hammering the endpoint again immediately. Beyond rate limits, the free API tier restricts access to NSFW content, which was explicitly excluded from the free data feed as of July 2023. Applications requiring NSFW data must negotiate commercial access with Reddit, which is priced at approximately $0.24 per 1,000 API calls as of the announced pricing structure, though exact terms for commercial agreements vary. Developer accounts are limited to three OAuth client IDs by default, and email verification is required to create new client IDs. Applications exceeding free-tier volume consistently must apply for and negotiate a paid commercial access agreement with Reddit's developer relations team. The API also does not guarantee full historical coverage. Reddit's search API returns a limited set of results for historical queries, and the decommissioning of Pushshift's public API access in 2023 removed the primary tool researchers had used to access complete historical Reddit data. Full historical access now requires either academic partnership agreements with Reddit or using Reddit's official data licensing program.