A Cloudflare Ray ID is an identifier given to every request that goes through Cloudflare. It is a unique identifier generated by Cloudflares edge servers and is included in the response headers of each request. Ray IDs are particularly useful when evaluating security events for patterns or false positives, or more generally understanding your application traffic. They are assigned to every request in the Cloudflare network, not just specific to errors.

Cloudflare customers can view Ray IDs and associated information such as IP address, user agent, ASN, etc. by looking through the Activity Log in Security Events. Enterprise customers can enable Ray ID as a field in their Cloudflare Logs. If a customer reports a problem, the site owner can easily ask for the Ray ID thrown with the error, and theyll be able to see the log for that request that went through Cloudflare.

If a user is having trouble accessing a website due to a Cloudflare error page, they can provide the Cloudflare Ray ID to the website owner to troubleshoot the exact reason why the user is not able to access the page. The website owner can then navigate to their Cloudflare Dashboard, look for Firewall > Overview, click the + Add Filter button just below Firewall Events, select Ray ID, enter the Ray ID that the user has provided, and click Apply to filter the events.