AI engineering glossary · Web APIs HTTP
What is 502 Bad Gateway?
502 Bad Gateway: The status code returned by a proxy or gateway when the upstream server it forwarded to gave an invalid answer or was unreachable. It usually signals a problem behind the front door.
502 Bad Gateway: an example
A reverse proxy returns 502 while the application behind it is restarting.
Related terms
More Web APIs HTTP terms
- 503 Service Unavailable
- 504 Gateway Timeout
- Accept header
- Access token
- API
- API gateway
- API key
- API pagination
Where you learn it
502 Bad Gateway is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.