523 Origin Is Unreachable
A Cloudflare error meaning it could not reach the origin server at all.
What it means
HTTP 523 is a non-standard Cloudflare status returned when Cloudflare cannot reach the origin server, usually because of a routing or DNS problem. The origin is effectively off the map from Cloudflare's point of view — there is no path to it.
When it happens
It happens when DNS points at the wrong or a non-existent IP, when the origin server has been moved or decommissioned, or when a network routing failure cuts Cloudflare off from the origin.
How to fix it
- Verify the DNS record in Cloudflare points to the correct, current origin IP address.
- Confirm the origin server exists and is reachable on the network.
- Check for routing problems or a misconfigured network between Cloudflare and the origin.
- Make sure the origin has not been moved without updating its IP in Cloudflare.
SEO impact
Damaging if sustained. An unreachable origin returns a server error to crawlers, so pages drop out of indexing until connectivity is restored.
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Related codes
A generic error meaning the server encountered an unexpected condition.
501 Not ImplementedThe server does not support the functionality required to fulfil the request.
502 Bad GatewayA server acting as a gateway received an invalid response from the upstream server.
503 Service UnavailableThe server is temporarily unable to handle the request, often due to overload or maintenance.
504 Gateway TimeoutA gateway server did not receive a timely response from the upstream server.
505 HTTP Version Not SupportedThe server does not support the HTTP protocol version used in the request.
Related guides
A plain-English primer on HTTP status codes for SEOs: what the 2xx, 3xx, 4xx, and 5xx families mean, which ones affect rankings, and the codes worth knowing.
How to find and fix broken linksA practical walkthrough for finding broken links on your site, working out why each one breaks, and fixing them so visitors and crawlers stop hitting dead ends.