303
3xx RedirectionSee Other
The response can be found at another URL using a GET request.
303 See Other tells the client to fetch a different URL with GET, no matter which method the original request used. Its main job is the POST-redirect-GET pattern: after a form submits, redirect with 303 so refreshing the result page doesn't resubmit the form. It differs from 302 by being explicit that the follow-up request must be a GET.
What 303 looks like on the wire
POST /orders HTTP/1.1 Host: shop.example.com Content-Type: application/json HTTP/1.1 303 See Other Location: /orders/5512/confirmation
About 3xx Redirection
Further action is needed to complete the request, usually following a redirect to another URL.
How to fix 303 See Other
- Use 303 after form submissions so a refresh doesn't trigger a duplicate POST.
- Point the Location header at the page that shows the result of the action.
- If the client must repeat the same method at the new URL, use 307 instead.
Where it's defined
303 See Other is defined in RFC 9110 §15.4.4. MDN's 303 reference covers browser behavior and examples.