Cloudflare
A global content delivery network and security company.
Cloudflare powers a significant portion of the web ecosystem, but like any complex technology, it has its own unique set of challenges. When you encounter an error on this platform, it is rarely a random event. It is usually a specific response to a misconfiguration, a resource limit, or a compatibility issue. Our documentation for Cloudflare is designed to cut through the noise. We don't just list the error codes; we explain the architecture behind them, helping you understand why the platform is rejecting your request or failing to load.
Common Errors
ERR_TOO_MANY_REDIRECTS
The ERR_TOO_MANY_REDIRECTS error, also known as a redirect loop, occurs when the website keeps redir...
Bad Gateway
A 502 Bad Gateway error indicates that a server acting as a gateway or proxy received an invalid res...
504 Gateway Timeout
The 504 Gateway Timeout error indicates that a server acting as a gateway or proxy did not receive a...
429 Too Many Requests
The 429 Too Many Requests error indicates that the user has sent too many requests in a given amount...
Error 521 Web Server Is Down
This is a Cloudflare-specific error indicating that the origin web server refused the connection fro...
Error 522 Connection Timed Out
This Cloudflare error happens when Cloudflare could not establish a TCP connection to the origin ser...
Web Server Returns an Unknown Error
Error 520 is a catch-all response from Cloudflare when the origin server returns something unexpecte...
Origin Is Unreachable
Error 523 occurs when Cloudflare cannot contact your origin web server. This is different from a tim...
A Timeout Occurred
Error 524 indicates that Cloudflare made a successful TCP connection to the origin server, but the s...
SSL Handshake Failed
Error 525 indicates that the SSL handshake between Cloudflare and the origin web server failed. This...
Invalid SSL Certificate
Error 526 occurs when Cloudflare is set to 'Full (Strict)' SSL mode, but the origin server's SSL cer...
Access Denied
Error 1020 Access Denied is a Cloudflare error that appears when a firewall rule violates the reques...
DNS Points to Prohibited IP
Error 1000 indicates that the DNS records for a Cloudflare-proxied domain are pointing to a Cloudfla...
You Are Being Rate Limited
Error 1015 indicates that the site owner has implemented rate limiting rules on their Cloudflare acc...
Origin DNS Error
Error 1016 Origin DNS Error occurs when Cloudflare attempts to connect to your origin server but can...
Argo Tunnel Error
Error 1033 indicates that the Cloudflare Argo Tunnel (now Cloudflare Tunnel) has failed. The cloudfl...
Railgun Listener to Origin Error
Error 527 indicates an interrupted connection between Cloudflare and the origin's Railgun server (rg...
Worker Threw Exception
Error 1101 indicates that a Cloudflare Worker (serverless script) threw a JavaScript exception durin...
CNAME Cross-User Ban
Error 1014 CNAME Cross-User Ban occurs when a CNAME record in one Cloudflare account points to a dom...
DNS Resolution Error
Error 1001 indicates that Cloudflare could not resolve the origin web server's hostname. This is sim...
Access Denied: Country or Region Banned
Error 1009 Access Denied indicates that the owner of the website has explicitly banned your country ...
Worker CPU Time Limit Exceeded
Error 1102 indicates that a Cloudflare Worker script exceeded the CPU time limit allocated to it. Cl...
Worker Memory Limit Exceeded
Error 1104 indicates that a Cloudflare Worker script attempted to consume more memory (RAM) than is ...
Connection timed out
Error 1004 indicates that Cloudflare was unable to establish a connection with the origin web server...
Worker script compilation error
Error 1105 signifies that Cloudflare was unable to successfully compile your Worker script. This typ...
Best Practices for Cloudflare Stability
Maintaining a stable Cloudflare environment requires proactive monitoring. Many of the errors listed above can be prevented by regular updates, proper caching configurations, and strict permission management. If you are a developer, ensure you are checking the platform's specific error logs, which often contain more detail than the public-facing error message.
Whether you are dealing with API rate limits, server timeouts, or authentication failures, the solutions provided here are tested and verified. Bookmark this page to have a quick reference guide whenever Cloudflare throws an unexpected exception.