lightmy.dayINSTANT ANSWERS

Server error

HTTP 503: Service Unavailable

HTTP 503 means the service is temporarily unavailable.

Meaning

The server cannot handle the request right now, often due to overload or maintenance.

Common causes

Maintenance windows, deploys, overloaded workers, or unavailable dependencies can cause it.

What to check

Check service health, capacity, maintenance status, and Retry-After behavior.

Example response

HTTP/1.1 503 Service Unavailable

References

Registry: IANA HTTP Status Code Registry
Spec: RFC 9110 §15.6.4
Guide: MDN 503 Service Unavailable

Related HTTP status codes

Nearby codes often answer the next debugging question.

429 Too Many RequestsHTTP 429 means the client sent too many requests.502 Bad GatewayHTTP 502 means a gateway received a bad response from an upstream server.504 Gateway TimeoutHTTP 504 means a gateway timed out waiting for an upstream server.