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5xx Series
Safe to retry
502 Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
🌍
SEO Impact
Negative. Tells crawlers the proxy layer is alive but the underlying application servers are dead or inaccessible.
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Common Causes
- 1Nginx failing to connect to Node/PM2 backends
- 2Docker container crash behind reverse proxy
Code Examples
Docker/Nginx
// Error typically thrown natively by Proxy/Load Balancers