Cloudflare Error 523: Origin is unreachable
Also searched as: error 523 · 523 origin is unreachable
Is Cloudflare Error 523 happening on your domain?
The DNS lookup shows exactly which address the record resolves to — which is where an unroutable target becomes obvious.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
Short answer
Cloudflare could not route to the origin at all. Typically the DNS record points at an invalid or unroutable IP, or the origin's network route has been withdrawn.
What Cloudflare Error 523 means
Where 522 is a timeout to a reachable address, 523 means the address itself is unroutable. The problem sits at the DNS or network layer, not the web server.
Causes and fixes, most likely first
The origin DNS record points at a private, reserved, or decommissioned IP.
Correct the A record to the server's current public address.
The origin's hosting provider withdrew the route (suspension, decommission).
Confirm the server is still provisioned and reachable from an independent network.
How to stop it happening again
- •Monitor DNS record values so a record pointing at a dead address is caught before the edge starts failing.
Frequently asked questions
Does 523 mean my server is off?
Not necessarily. It means the address Cloudflare was told to use cannot be reached. The server may be fine at a different address.