405 Method Not Allowed

Client error: the problem lies with the request. Repeating it unchanged will normally fail again.

When a server should send it. When the URL exists but does not support the method used, such as DELETE on a read-only resource. The response must list the methods it does accept in an Allow header.

Common causes. Calling an API endpoint with the wrong method, or a form posting to a static page.

What to do. Use a method listed in the Allow header of the response.

Browsers and HTTP clients. Browsers show the body; it mostly surfaces when a form posts to a static file. API clients read Allow to see what is supported.

Google Search. Like every 4xx except 429, it tells Google the content does not exist: an indexed URL is removed from the index, and a new one is not processed. Crawl frequency for the URL gradually drops. Source: Google Search Central, How HTTP status codes, and network and DNS errors affect Google Search.

Caching. Cacheable by default (RFC 9110 section 15.1). With no Cache-Control or Expires header, a cache may still store it and reuse it for a heuristic period, often 10% of the time since Last-Modified, so set Cache-Control explicitly if that is not what you want.

HTTP/1.1 405 Method Not Allowed
Allow: GET, HEAD
Content-Type: text/plain

Method Not Allowed

location /example {
    add_header Allow 'GET, HEAD' always;
    return 405;
}

Header always set Allow "GET, HEAD"
RewriteEngine On
RewriteRule ^example$ - [R=405,L]

header('Allow: GET, HEAD');
http_response_code(405);
echo 'Method Not Allowed';
exit;

res.writeHead(405, { 'Allow': 'GET, HEAD', 'Content-Type': 'text/plain' });
res.end('Method Not Allowed');

# in a view function
return 'Method Not Allowed', 405, {'Allow': 'GET, HEAD'}