Loading AI tools
HTTP response status code From Wikipedia, the free encyclopedia
The 502 Bad Gateway error is an HTTP status code that occurs when a server acting as a gateway or proxy receives an invalid or faulty response from another server in the communication chain.[1] This error indicates a problem with the communication between the involved servers and can result in disruption of internet services. The 502 Bad Gateway error is considered one of the most common error codes on the internet and can occur in various scenarios.
![]() | The article's lead section may need to be rewritten. (July 2024) |
The 502 Bad Gateway error is defined in the RFC 7231[2] specification, in Section 6.6.3.[3] The 502 Bad Gateway error is part of the Hypertext Transfer Protocol (HTTP) specification. It is defined in the HTTP/1.1 specification by the World Wide Web Consortium (W3C). According to the specification, the 502 status code indicates that the server, while acting as a gateway or proxy, received an invalid response from an upstream server.
The 502 Bad Gateway error can occur due to several reasons. Some of the common causes include:[4]
Consider the following example to illustrate the occurrence of a 502 Bad Gateway error:
A user attempts to access a website by entering the URL in their browser. A proxy server first receives the user's request. Acting as an intermediary, the proxy server forwards the request to an upstream server. The upstream server processes the request but encounters an internal error. Instead of sending a valid response, the upstream server returns an invalid or faulty response to the proxy server. The proxy server, unable to handle the invalid response, returns a 502 Bad Gateway error to the user's browser. The user sees the error page indicating the 502 Bad Gateway status.[5]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.