301 Moved Permanently
301 Moved Permanently tells a client that the resource they’re trying
to access has moved to a new location. The server will include the new
location in the Location header.
When a client sees this response, it should repeat the same request on the new location, and if it can, it should also update any links it may have had to the old location and update it to the new one.
Example
HTTP/1.1 301 Moved Permanently
Server: Curveball/0.4.2
Location: https://evertpot.com/http/301-moved-permanently
Real-world Usage
According to the specifications, a client should repeat the exact same request on the new location. In practice, a lot of clients don’t do this.
The reality is that when many clients do something like a POST request
on a resource that responds with a 301, almost every client will assume that
the POST was successful and do a GET request on the new resource for
additional information, including browsers.
This incorrect behavior was so common, that when the HTTP specifications were
updated, the newer documents mention this behavior. In addition, a new
status-code was introduced later that restored the original behavior:
308 Permanent Redirect.
References
- RFC7231, Section 6.4.2 - 301 Moved Permantently
- RFC7238 - 308 Permanent Redirect