HTTP status codes that Bing Web Search API may return


If you are using the Bing APIs, bring your own LLM S15 instance and expect to exceed the 1M queries per day quota, you should consider implementing monitoring to detect when you are nearing your limit so you can automate switching to the next tier, S16.

The following are the possible HTTP status codes that a request may return.

Status code Description
200 Success.
400 One of the query parameters is missing or not valid.
401 The subscription key is missing or is not valid.
403 The user is authenticated (for example, they used a valid subscription key) but they don’t have permission to the requested resource.

Bing may also return this status if the caller exceeded their queries per day or queries per month quota.
410 The request used HTTP instead of the HTTPS protocol. HTTPS is the only supported protocol.
429 The caller exceeded their queries per second quota.
500 Unexpected server error.

If the request fails, the response contains an ErrorResponse object, which contains a list of Error objects that describe what caused the error. If the error is related to a parameter, the parameter field identifies the parameter that caused the issue. And if the error is related to a parameter value, the value field identifies the value that is not valid.

  "_type": "ErrorResponse", 
  "errors": [
      "code": "InvalidRequest", 
      "subCode": "ParameterMissing", 
      "message": "Required parameter is missing.", 
      "parameter": "q" 

  "_type": "ErrorResponse", 
  "errors": [
      "code": "InvalidAuthorization", 
      "subCode": "AuthorizationMissing", 
      "message": "Authorization is required.", 
      "moreDetails": "Subscription key is not recognized."

Error codes

The following are the possible error code and sub-error code values.

Error code SubCode Description
ServerError UnexpectedError
HTTP status code is 500.
InvalidRequest ParameterMissing
Bing returns InvalidRequest whenever any part of the request is not valid. For example, a required parameter is missing or a parameter value is not valid.

If the error is ParameterMissing or ParameterInvalidValue, the HTTP status code is 400.

If you use the HTTP protocol instead of HTTPS, Bing returns HttpNotAllowed, and the HTTP status code is 410.
RateLimitExceeded No sub-codes Bing returns RateLimitExceeded whenever you exceed your queries per second (QPS) or queries per month (QPM) quota.

If you exceed QPS, Bing returns HTTP status code 429, and if you exceed QPM, Bing returns 403.
InvalidAuthorization AuthorizationMissing
Bing returns InvalidAuthorization when Bing cannot authenticate the caller. For example, the Ocp-Apim-Subscription-Key header is missing or the subscription key is not valid.

Redundancy occurs if you specify more than one authentication method.

If the error is InvalidAuthorization, the HTTP status code is 401.
InsufficientAuthorization AuthorizationDisabled
Bing returns InsufficientAuthorization when the caller does not have permissions to access the resource. This can occur if the subscription key has been disabled or has expired.

If the error is InsufficientAuthorization, the HTTP status code is 403.