405 Method Not Allowed

The resource exists but does not support the HTTP method used.

405 at a glance

Code: 405
Name: Method Not Allowed
Class: 4xx Client error
Status: IANA-registered standard code
Defined in: RFC 9110, Section 15.5.6
Cacheable by default: Yes, heuristically cacheable (RFC 9110 section 15.1): without Cache-Control or Expires, caches may store it and pick a freshness lifetime themselves. Send explicit Cache-Control to stay in control.

What 405 means

405 Method Not Allowed says the target resource is known but rejects this method, for example a DELETE on a read-only resource or a POST to a static file. The server must include an Allow header listing the methods it does support. 405 is heuristically cacheable.

What typically causes a 405

nginx answers "405 Not Allowed" to POST requests for static files.
Framework routes defined only for GET receiving POST (Flask, Django, Express all send 405 when the path matches but the method does not).
Form submissions to the wrong URL, or a missing trailing slash causing a redirect that turns POST into GET.
WebDAV methods (PROPFIND, MKCOL) sent to servers without WebDAV enabled.

Fix it on the server

Include Allow, e.g. Allow: GET, HEAD.
Answer OPTIONS correctly, especially for CORS preflights; a 405 on OPTIONS breaks cross-origin requests.

Fix it as a client or visitor

Check the API docs for the correct method and URL; send the request to the final URL rather than through a redirect.

Headers that go with 405

Header	Role
`Allow`	Required: methods the resource supports.

Example response

HTTP/1.1 405 Method Not Allowed
Allow: GET, HEAD, OPTIONS
Content-Type: application/json

{"error": "Method POST not allowed"}