Rate limits for specific endpoints can be found in the API reference for each endpoint.
All new API endpoints are rate limited on a per-account basis, and used a fixed-window rate limiting algorithm with two distinct windows: burst (short) and steady (long). All API traffic will be subject to these rate limits, and will receive
HTTP 429 errors in event either a burst or steady rate limit is reached.
Unless otherwise documented, all API endpoints use one of the following rate limits:
- S: 3/s burst; 60/m steady
- M: 10/s burst; 150/m steady
- L: 75/s burst; 700/m steady
- XL: 350/s burst; 3500/m steady
All non-rate-limited (i.e. non 429) responses will contain the following HTTP response headers that indicate the state of the steady rate limit window to the client:
RateLimit–Limit: The number of requests allowed per time period
RateLimit-Remaining: The approximate number of requests remaining within a window
RateLimit-Reset: Number of seconds remaining before current window resets
Klaviyo's event tracking endpoints use ingestion limits to prevent processing delays and service interruptions to the event ingestion pipeline. If you are using a Klaviyo webhook, custom integration, or API implementation, it is important to be aware of the limits on the events you send into Klaviyo. The table below provides guidance on the maximum sizes for your payload and its fields.
Endpoints with ingestion limits:
|Max payload size||5 MB decompressed|
|Max number of event properties per data packet||300|
|Max size of any field||100 kB|
|Max number of items in arrays||4000|
|Max levels of nested objects||10|
|Timestamp of events||Between 2000 and “now”+1 year|
Our API uses conventional HTTP response codes to indicate success or failure of an API request. Errors typically fall into three ranges:
- 2xx - Success
- 4xx - Error as a result of information provided as part of the request, such as a requested object that doesn't exist, an invalid setting, etc.
- 5xx - Error due to Klaviyo
The response of all API errors contain a
message parameter which has developer-facing information about why the request failed.
See the table below for a list of error codes and their corresponding descriptions:
|200||OK||The request completed successfully|
|400||Bad Request||Request is missing or has a bad parameter|
|400||Not Authorized||Request is missing or has an invalid API key|
|401||Not Authorized||Key is valid, but account does not have permissions to perform this action|
|403||Forbidden||Request is missing or has an invalid API key|
|404||Not Found||The requested resource doesn't exist|
|429||Rate Limit||You hit the rate limit for this endpoint (different endpoints have different rate limits)|
|500||Server Error||Something is wrong on Klaviyo's end|
Updated about 2 months ago