523 Origin is unreachable
HTTP response status code 523 Origin is unreachable is an unofficial server error that is specific to Cloudflare. This HTTP status code occurs when there is an error with the origin server and it cannot be reached.
Cloudflare is a content delivery network that acts as a gateway between a user and a website server. When the 523 Origin is unreachable status code is received, the Cloudflare server is unable to reach the origin server and is most likely due to a DNS-related error.
The 523 Origin is unreachable status code is a Cloudflare-specific server error that is generated because Cloudflare was not able to reach the origin server.