502
5xxSEO: criticalRFC 9110
HTTP 502 Bad Gateway
An upstream server returned an invalid response. Common during deployments and traffic spikes.
Indexable by Google
No
Link equity passed
No
SEO Impact
Critical
Category
5XX
SEO Impact
502 typically means your reverse proxy (Nginx/Cloudflare) could not get a valid response from your application server. From an SEO perspective, it behaves like 500 — sustained 502s lead to deindexing. Common causes: deployment downtime, application crashes, database timeouts, origin server overload. If you see 502s in Search Console, check your server error logs and application health.
When to Use 502
Automatically returned by proxy servers when the origin is unavailable — not manually configured.
HTTP Response Example
HTTP/1.1 502 Bad Gateway Content-Type: text/html
Test with cURL
$ curl -I https://example.com/