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DocsUsage & Limits

Usage & Rate Limits

Understand how we measure API usage and the limits applied to ensure high reliability and performance for all users.

Fair Use Policy

pdftheory is currently free to use with reasonable limits. To maintain quality of service, we implement rate limits based on your account tier.

Free Tier
100 requests
per day
Wait Period
1 request
per second
File Size
50 MB
per upload

Rate Limit Headers

Every API response includes standard HTTP headers indicating your current usage and remaining quota.

HeaderDescription
x-ratelimit-limitThe total number of requests allowed per period.
x-ratelimit-remainingThe number of requests remaining in the current window.
x-ratelimit-resetThe time at which the current limit resets (Unix timestamp).

Limit Exceeded Code

When you exceed a rate limit, the API will return a 429 Too Many Requestsstatus code. Your integration should handle this gracefully with an exponential backoff strategy.