HTTP 502 Bad Gateway — Meaning

502 Bad Gateway means a gateway or proxy received an invalid response from the upstream server — e.g. the app behind an L7 load balancer is down or returned invalid headers.

Key facts

Frequently asked questions

What does 502 mean?

A proxy/gateway got an invalid response from the upstream server.

Common cause of 502?

The upstream app is down behind a load balancer or returned bad headers.

Related pages

• HTTP 200 OK
• HTTP 301 Moved Permanently
• HTTP 401 Unauthorized
• HTTP 403 Forbidden
• HTTP 404 Not Found
• HTTP 429 Too Many Requests
• HTTP 500 Internal Server Error
• HTTP 503 Service Unavailable

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