HTTP Status Codes

HTTP 200: OK
Standard response, everything is OK. The response body will include the data, if applicable.
HTTP 400: Bad Request

There was a problem understanding the request sent to the service.  In most cases this means the code that generated the request has a bug and generated a malformed HTTP request.  For example a common problem is if the length of the request doesn't match the Content-Length header sent to the service.

HTTP 401: Unauthorized
The API Key is invalid. The response body will indicate the error condition.
HTTP 404: Unauthorized

There was a problem locating the resource you requested. Either check the spelling of the key or id given, or it's possible the resource no longer exists.

HTTP 503: Unavailable
It's possible you've bumped up against the API limits, and have been throttled. Try again in a short while.
This guide was first published on Jan 22, 2015. It was last updated on Oct 22, 2018. This page (HTTP Status Codes) was last updated on Oct 08, 2018.