cloudflare

Cloudflare Error Codes

Error codes returned by Cloudflare's reverse proxy and CDN network. Includes 1xxx browser-displayed errors for DNS and connectivity issues, and 5xx HTTP status codes for origin-side failures.

29 codes

references developers.cloudflare.com/support/troubleshooting/cloudflare-errors/

· All codes 29 codes

520 Web Server Is Returning an Unknown Error The origin server returned an empty, unknown, or unexpected response to Cloudflare. This is a catch-all for origin errors that do not fit a more specific category.
521 Web Server Is Down The origin server refused the TCP connection from Cloudflare. The origin may be offline, overloaded, or blocking Cloudflare's IP ranges.
522 Connection Timed Out Cloudflare was unable to reach the origin server within the connection timeout period. The origin may be overloaded, unreachable, or firewalled against Cloudflare's IPs.
523 Origin Is Unreachable Cloudflare cannot reach the origin because DNS resolution for the origin hostname failed. Check that the origin's DNS records are correct and that the host is reachable.
524 A Timeout Occurred The origin server established a TCP connection with Cloudflare but did not send a response within the 100-second read timeout. The origin may be performing a long-running operation.
525 SSL Handshake Failed Cloudflare could not complete the TLS handshake with the origin server. The origin may not support the cipher suites or TLS versions that Cloudflare uses, or the SSL certificate may be misconfigured.
526 Invalid SSL Certificate Cloudflare could not validate the SSL certificate presented by the origin server. The certificate may be self-signed, expired, or issued by an untrusted authority while Full (Strict) SSL mode is enabled.
527 Railgun Listener to Origin Error An error occurred in the Cloudflare Railgun connection between the Railgun Listener and the origin server. Railgun is a legacy WAN optimization product that has been deprecated.
530 Origin DNS Error Cloudflare received a 530 status in combination with a 1xxx error displayed in the response body, indicating an origin DNS lookup failure. Refer to the accompanying 1xxx error code for the specific cause.
1000 DNS Points to Prohibited IP Cloudflare resolved the hostname but the resulting IP address is one it cannot proxy to, such as a Cloudflare IP or a loopback address. Update the DNS record to point to the correct origin IP.
1001 DNS Resolution Error Cloudflare could not resolve the requested hostname. The domain may not exist or its DNS records may be misconfigured.
1002 Restricted The hostname resolves to a prohibited IP address, or the domain is configured to redirect to a Cloudflare IP. Check that the DNS record points to a valid, non-restricted origin.
1003 Direct IP Access Not Allowed The site was accessed by its IP address rather than its domain name, and the zone does not permit direct IP access. Access the site using its hostname instead.
1004 Host Not Configured to Serve Web Traffic The hostname is not configured to serve web traffic through Cloudflare. The DNS record may exist but the host has not been set up to handle HTTP requests.
1006 Access Denied — IP Banned The visitor's IP address has been banned by the site owner. The ban can be configured through Cloudflare's IP Access Rules.
1007 Access Denied — IP Banned The visitor's IP address has been banned by the site owner. The ban can be configured through Cloudflare's IP Access Rules.
1008 Access Denied — ASN Banned The visitor's Autonomous System Number (ASN) has been banned by the site owner. The entire IP range belonging to the ASN is blocked via Cloudflare's IP Access Rules.
1009 Access Denied — Country or Region Banned The visitor's country or region has been blocked by the site owner using Cloudflare's IP Access Rules. Requests originating from that geographic area are denied.
1010 Access Denied — Hotlinking Blocked The request was blocked because the resource is being hotlinked from another site and the site owner has restricted direct linking to their resources.
1011 Access Denied — Hotlink Protection Enabled Cloudflare's Hotlink Protection feature is enabled and blocked this request because the resource was referenced from an external site. Only direct navigation and same-origin requests are permitted.
1012 Access Denied — IP Lockdown Rule An IP Lockdown rule is configured for this resource, restricting access to a specific set of IP addresses. The visitor's IP is not on the allowed list.
1013 HTTP Hostname and TLS SNI Hostname Mismatch The hostname in the HTTP Host header does not match the hostname sent in the TLS SNI extension. This can indicate a misconfigured client or a proxy that is not forwarding SNI correctly.
1014 CNAME Cross-User Banned A CNAME record points to a hostname in a different Cloudflare account, which is not permitted. The CNAME target must belong to the same Cloudflare account or be configured to allow cross-account CNAMEs.
1015 You Are Being Rate Limited The visitor has exceeded a rate limit configured by the site owner and is being temporarily blocked. Requests will be permitted again once the rate limit window resets.
1016 Origin DNS Error Cloudflare cannot resolve the origin server's hostname in its DNS settings. The DNS record for the origin may be missing, incorrect, or propagating.
1018 Cannot Find Host The requested domain was not found in Cloudflare's system. The domain may not be active on Cloudflare, or its zone may have been deleted or suspended.
1019 Compute Server Error A Cloudflare Workers script encountered a runtime error. The Worker threw an unhandled exception or hit a resource limit during execution.
1020 Access Denied — Blocked by Firewall Rule The request was blocked by a Cloudflare WAF custom firewall rule or managed rule configured by the site owner. The visitor's request matched a rule set to block.
1023 Could Not Find Host Cloudflare could not identify the host for this request. The domain may not be properly configured in Cloudflare or the request is missing a valid Host header.