503

Service Unavailable

Description

The server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded. Note that together with this response, a user-friendly page explaining the problem should be sent.

HTTP Status Codes Details

Status Code
503
Status Name
Service Unavailable
Class
5xx
Common Usage
Yes

Common Scenarios

  • Server-side errors
  • Service unavailable

Handling Recommendations

  • Implement retry logic
  • Monitor server health

Was this helpful?

Loading...

Send Feedback

Found an error or have a suggestion? We respond within 48 hours.

Fact-checking completed

Verified by: Pavel Volkov
Created:
Last updated:
Information verified against official sources

Official Sources

Internet Engineering Task Force RFCs

Official HTTP status codes specification (RFC 7231)

Internet standards organization defining HTTP protocols

Visit

Mozilla Developer Network

Comprehensive HTTP status codes documentation

Authoritative web development documentation

Visit

Internet Assigned Numbers Authority

Official HTTP status code registry

Internet protocol parameters authority

Visit

Learn More

Dive deeper with our comprehensive developer guides for HTTP Status Codes

Complete Guide to HTTP Status Codes

Master HTTP status codes with our comprehensive guide. Learn about all 1xx, 2xx, 3xx, 4xx, and 5xx c...

Pavel Volkov Aug 30, 2025
View all guides

Related Codes

More codes of the same type

451

Unavailable For Legal Reasons

The user agent requested a resource that cannot legally be provided, such as a w...

View details →

500

Internal Server Error

The server has encountered a situation it doesn't know how to handle. This is a...

View details →

501

Not Implemented

The request method is not supported by the server and cannot be handled. The onl...

View details →

502

Bad Gateway

This error response means that the server, while working as a gateway to get a r...

View details →

504

Gateway Timeout

This error response is given when the server is acting as a gateway and cannot g...

View details →

505

HTTP Version Not Supported

The HTTP version used in the request is not supported by the server. This might...

View details →

506

Variant Also Negotiates

The server has an internal configuration error: the chosen variant resource is c...

View details →

507

Insufficient Storage

The method could not be performed on the resource because the server is unable t...

View details →
Back to HTTP Status Codes