HTTP 301 Moved Permanently vs 409 Conflict
HTTP 301 (Moved Permanently) is a 3xx Redirection response, while 409 (Conflict) 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, 409 means that the request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
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 request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
When You See It
When trying to create a resource that already exists, or updating a resource that was modified by another request.
How to Fix
Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.
Key Differences
301 is a 3xx Redirection response, while 409 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 409: The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
You encounter 301 when after domain migrations, URL restructuring, or when consolidating duplicate URLs.
You encounter 409 when when trying to create a resource that already exists, or updating a resource that was modified by another request.
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 409 (Conflict): Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.