All HTTP Status Codes
502

Bad Gateway

5xx Server Error

What It Means

The server received an invalid response from an upstream server while acting as a gateway.

When You'll See It

Common with reverse proxies (Nginx, load balancers) when the upstream application server is down.

Related Status Codes

503 Service Unavailable 504 Gateway Timeout 500 Internal Server Error

Frequently Asked Questions

What does HTTP 502 mean?

HTTP 502 Bad Gateway means: The server received an invalid response from an upstream server while acting as a gateway.

When does a server return 502?

Common with reverse proxies (Nginx, load balancers) when the upstream application server is down.

Is 502 a client error or server error?

HTTP 502 is a Server Error (5xx) response. This means the issue is on the server side — the server failed to fulfill a valid request.

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