HTTP 503 Service Unavailable

Server Error

The server is temporarily unable to handle the request, usually due to maintenance or overloading. The server may send a Retry-After header.

Common Causes

Server is under maintenance
Server is overloaded with too many requests
Application pool or worker process limit reached
Deployment in progress

How to Fix

Wait and retry after the Retry-After period
Check server load and scale resources if needed
Verify maintenance status with the operations team
Check application pool and worker process configuration

Related Status Codes

500 Internal Server Error 502 Bad Gateway 429 Too Many Requests

Need to look up other HTTP status codes?

View the Full HTTP Status Code Reference