503
Service Unavailable
Server Error
Description
The server is currently unavailable (overloaded or down for maintenance)
Common Usage
Temporary server downtime; often includes Retry-After header
Example Response
How this status code appears in HTTP responses
HTTP Response Header
HTTP/1.1 503 Service UnavailablecURL Example
curl -I https://example.com
# Returns: HTTP/1.1 503 Service UnavailableServer Error Response
This is a server error response indicating the server failed to fulfill a valid request.
Related Server Error Codes
Other codes in the same category
500
Internal Server Error
A generic error message when the server encounters an unexpected condition
501
Not Implemented
The server does not support the functionality required to fulfill the request
502
Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server