Rate limits
How many requests per second you can send, the headers that tell you where you stand, and how to handle 429s.
| Account | Requests per second | Burst |
|---|---|---|
| Free credits only | 5 | 10 |
| Has prepaid credits | 50 | 100 |
Limits apply per account, across all of its keys. Need more? Contact us.
Headers
Every check response tells you where you are:
| Header | Meaning |
|---|---|
RateLimit-Limit |
Requests per second allowed. |
RateLimit-Remaining |
Requests left in the current burst. |
Retry-After |
On a 429 only: seconds to wait before retrying. |
Handling a 429
Wait for Retry-After seconds and send the same request again. Rate-limited requests are never charged.
For bulk work, such as cleaning an existing list, use /v1/email/batch. It checks up to 100 addresses in one request.