Rate Limits
PDFBolt enforces rate limits to ensure stable performance and fair usage for all customers. Limits depend on your plan.
Rate Limits per Plan
| Plan | Per minute | Concurrent |
|---|---|---|
| Free | 20 | 1 |
| Basic | 100 | 5 |
| Growth | 250 | 20 |
| Enterprise | 500 | 50 |
Need higher limits? Contact us for a custom plan.
How Rate Limits Work
PDFBolt uses a sliding window algorithm. Your usage is tracked in real time across the per-minute, per-hour, and per-day windows. When you reach any limit, further requests are temporarily blocked with HTTP 429 until your usage drops below the limit.
The concurrent request limit restricts how many requests can be processed at the same time. Requests that exceed this limit are rejected immediately with HTTP 429.
For /v1/async, the concurrent limit applies to the acceptance of conversion requests. Once accepted, conversions may run in parallel without counting against the concurrent limit.
Limits in Response Headers
PDFBolt returns rate limit usage in every successful API response so you can monitor your usage in real time:
| Header | Description |
|---|---|
x-pdfbolt-limit-day | Total allowed requests per rolling 24-hour window. |
x-pdfbolt-limit-hour | Total allowed requests per rolling 1-hour window. |
x-pdfbolt-limit-minute | Total allowed requests per rolling 1-minute window. |
x-pdfbolt-remaining-day | Remaining requests in the rolling 24-hour window. |
x-pdfbolt-remaining-hour | Remaining requests in the rolling 1-hour window. |
x-pdfbolt-remaining-minute | Remaining requests in the rolling 1-minute window. |
Exceeding Rate Limits
When you exceed any rate limit, the API returns HTTP 429 Too Many Requests. PDFBolt does not return a Retry-After header, so use exponential backoff to determine retry timing.
For details on this and other errors, see the Error Handling documentation.
Need Higher Limits?
If your application requires higher throughput or custom limits, contact us. We offer tailored plans with higher rate limits and more concurrent requests.