Error map
Cloudflare 502 Cloudflare-branded 502 Bad Gateway / 504 Gateway Timeout ("cloudflare" footer)
Cloudflare · layer 3, Edge & web server
Centre: this error. First ring: errors it is linked with (7). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (7)
Cloudflare Error 520: Web Server Returned an Unknown Error
Cloudflare connected to your origin, but the origin returned an empty, unknown or invalid response.
HTTP 502 Bad Gateway
A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.
HTTP 504 Gateway Timeout
A proxy or gateway waited too long for the upstream server to respond and gave up.
Cloudflare Error 1016: Origin DNS error
Cloudflare can’t resolve the origin hostname your DNS record points to (usually a CNAME target).
Cloudflare Error 1200: Cache connection limit
Too many requests are queued at Cloudflare for the origin — the origin is slow and connections pile up.
Cloudflare Error 1033: Argo Tunnel error (Cloudflare Tunnel not connected)
The hostname routes to a Cloudflare Tunnel, but no healthy cloudflared connector is running for it.
cloudflared: Unable to reach the origin service. The service may be down or it may not be responding to traffic from cloudflared (502)
The tunnel is connected, but cloudflared can’t reach your local service at the address in the ingress rule.
Two steps away (17)
HTTP 500 Internal Server Error
The server hit an unexpected condition — usually an unhandled exception or misconfiguration in the application.
Cloudflare Error 521: Web Server Is Down
Cloudflare couldn’t connect to your origin — the connection was refused.
HTTP 301 Moved Permanently
The resource has a new permanent URL; clients and search engines should use the address in the Location header from now on.
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
HTTP 407 Proxy Authentication Required
A proxy between you and the server requires credentials before it will forward your request.
HTTP 503 Service Unavailable
The server is temporarily unable to handle the request — overloaded, in maintenance, or has no healthy backends.
HTTP 408 Request Timeout
The server closed the connection because the client took too long to send the complete request.
HTTP 499 Client Closed Request (Nginx)
Nginx-specific code logged when the client disconnected before the server finished responding.
PHP Fatal error: Maximum execution time of 30 seconds exceeded
The script ran longer than `max_execution_time` and PHP stopped it.
Cloudflare Error 523: Origin is unreachable
Cloudflare can’t find a network route to your origin server — the DNS record points to a wrong/unroutable IP or the origin networ…
Cloudflare HTTP 530 (with Error 1016 Origin DNS error / 1033 tunnel error)
Cloudflare returns 530 together with a 1xxx error; the 1xxx code (usually 1016 or 1033) tells you the real cause.
Cloudflare Error 1000: DNS points to prohibited IP
A proxied DNS record points at a Cloudflare IP address, creating a loop.
Cloudflare Error 524: A Timeout Occurred
Cloudflare connected to the origin, but the origin didn’t send an HTTP response within 100 seconds.
HTTP 304 Not Modified
The cached copy is still valid, so the server sends no body and the client reuses its cache.
HTTP 412 Precondition Failed
A conditional request header (If-Match, If-Unmodified-Since) didn’t match the current state of the resource.
Cloudflare Error 1002: DNS points to Prohibited IP / Restricted
A record points to a private, reserved or Cloudflare IP that Cloudflare won’t proxy to.
NET::ERR_CERT_AUTHORITY_INVALID with a Cloudflare Origin Certificate (record not proxied)
Cloudflare Origin CA certificates are only trusted by Cloudflare — visitors reaching the origin directly (grey-cloud record, dire…
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