HTTP 501 Not Implemented: Meaning & How to Fix

Quick answer

HTTP status code 501 (Not Implemented) means: The server does not support the function needed to complete the request. Yes, a server error: the website failed to handle the request. Usually only the site owner or host can fix it.

Is it an error?

5xx Server errors

Yes, a server error: the website failed to handle the request. Usually only the site owner or host can fix it.

The server failed to handle a valid request; the problem is on the website's side.

Common causes

Request method not supported for this URL
Client and server do not support the same protocol or version

If you are visiting the site

Update your browser or app
Contact the website if the problem continues

If you run the website

Allow the method on this route or send an Allow header
Review recent configuration changes (.htaccess, nginx/Apache rules)

Frequently asked questions

What does HTTP 501 mean?

HTTP status code 501 (Not Implemented) means: The server does not support the function needed to complete the request.

Is HTTP 501 an error?

Yes, a server error: the website failed to handle the request. Usually only the site owner or host can fix it.

How do I fix a 501 error?

If you are visiting the site: Update your browser or app; Contact the website if the problem continues. If you run the website: Allow the method on this route or send an Allow header; Review recent configuration changes (.htaccess, nginx/Apache rules).

5xx Server errors

HTTP 500 Internal Server ErrorThe server hit an unexpected error and could not complete the request.HTTP 502 Bad GatewayA gateway or proxy server received an invalid response from the server behind it.HTTP 503 Service UnavailableThe server is temporarily unable to handle the request because it is overloaded or under maintenance.HTTP 504 Gateway TimeoutA gateway or proxy server did not get a response in time from the server behind it.HTTP 505 HTTP Version Not SupportedThe server does not support the HTTP version used in the request.HTTP 507 Insufficient StorageThe server does not have enough storage space to complete the request.HTTP 508 Loop DetectedThe server detected an infinite loop while processing the request.HTTP 511 Network Authentication RequiredYou must sign in to the network (for example hotel, airport or public Wi-Fi) before you can use the internet.