| title | Errors & rate limits |
|---|---|
| description | Error responses of the LeakCheck API and the request-rate limits that apply. |
The API reports failures with a standard HTTP status code and an error message describing the condition:
| Error | Status code | Notes |
|---|---|---|
| Missing X-API-Key header | 401 | No API key provided in the request header. |
| Invalid X-API-Key | 400 | The API key provided is invalid. |
| Invalid type | 400 | The type parameter is not one of the supported values. |
| Invalid email | 400 | The email format is incorrect. |
| Invalid query | 400 | The query format is invalid. |
| Invalid domain | 400 | The domain format is invalid. |
| Too short query (< 3 characters) | 400 | The query must be at least 3 characters long. |
| Invalid characters in query | 400 | The query contains characters that are not allowed. |
| Too many requests | 429 | You have exceeded the rate limit — see below. |
| Active plan required | 403 | A paid plan is required to make this request. |
| Limit reached | 403 | You have reached your plan's usage quota. |
| Could not determine search type automatically | 422 | Auto-detection failed — pass an explicit type parameter. |
Handle 429 responses by backing off and retrying; treat 403 as a signal
to check your plan status or remaining quota (the quota field of every
successful response tells you how many queries you have left).
| API | Limit | Notes |
|---|---|---|
| Pro API v2 | 3 requests / second | Applies to any plan; can be increased in settings. |
| Public API | 1 request / second | Fixed. |
By default, the Pro API is limited to 3 requests per second on any plan. You can increase this limit in your account settings.