HTTP headers / response header
Location: https://api.example.com/v1/users/4521
Where to go next: the redirect target on 3xx responses, or the URL of the freshly created resource on 201.
Relative Locations are legal and clients must resolve them against the request URL — hand-rolled redirect followers often get this wrong.
The fastest way to see what Location is actually doing is to send the request and read both sides raw — ReqPad shows auto-generated and custom headers for every request, on all six protocols, with history. Related references: status codes · WWW-Authenticate · Content-Encoding · Transfer-Encoding · ETag · Last-Modified · Expires
Build the request, send it, read raw headers and timing — from your iPhone. Free to start.