HTTP 301 Moved Permanently vs 411 Length Required
HTTP 301 (Moved Permanently) is a 3xx Redirection response, while 411 (Length Required) is a 4xx Client Error response. 301 indicates that the resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL. In contrast, 411 means that the server refuses to accept the request without a Content-Length header.
Description
The resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL.
When You See It
After domain migrations, URL restructuring, or when consolidating duplicate URLs.
How to Fix
Update links and bookmarks to the new URL in the Location header. For SEO, this is the preferred redirect for permanent moves.
Description
The server refuses to accept the request without a Content-Length header.
When You See It
When sending a request body without specifying Content-Length.
How to Fix
Include a Content-Length header in your request.
Key Differences
301 is a 3xx Redirection response, while 411 is a 4xx Client Error response.
HTTP 301: The resource has been permanently moved to a new URL. All future requests should use the new URL. Search engines will transfer link equity to the new URL.
HTTP 411: The server refuses to accept the request without a Content-Length header.
You encounter 301 when after domain migrations, URL restructuring, or when consolidating duplicate URLs.
You encounter 411 when when sending a request body without specifying Content-Length.
When to Use Which
For 301 (Moved Permanently): Update links and bookmarks to the new URL in the Location header. For SEO, this is the preferred redirect for permanent moves. For 411 (Length Required): Include a Content-Length header in your request.