Error Code Portal
CloudflareCloudflare HTTP errorsError code

501

Error 501: not implemented

Alternative forms: Error 501

What does this code mean?

Code 501 · An issue reported by Cloudflare HTTP errors.

Official explanation · Original text

Cloudflare Workers returns a 501 error when a request uses an HTTP method that is not supported by the Workers Runtime. - A client sent a request to a Workers script using a custom or non-standard HTTP method (methods outside of GET, POST, PUT, etc.). - A typo in the HTTP method (for example, POT instead of POST).

Troubleshooting and diagnostic links

First check that the document's product, version, and environment match your situation.

Source and terms of use

Error 501: not implemented ↗

Creator: Cloudflare, Inc. and contributors
License: Creative Commons Attribution 4.0 International
Checked on: 2026-11-12

Modifications: Selected introductory official description; Markdown stripped; original Korean product context added. Direct official error page retains the complete cause and resolution instructions.

Source details · Original licenses and notices