See Other

Overview

303 See Other instructs the client to fetch the response from a different URL using GET. Even if the original request was a POST, the redirected request is specified to become a GET.

This makes it the standard tool for the Post/Redirect/Get (PRG) pattern: after a form submission you redirect to a result page, so refreshing does not resubmit the POST and you avoid duplicate orders or sign-ups.

When it happens

• Use it after handling a form submission (POST) to send the browser to a result or confirmation page via GET.
• It fits telling a client to view the outcome at a separate URL after long processing or a file upload.

Request / Response example

POST /orders HTTP/1.1
Host: shop.example.com
Content-Type: application/x-www-form-urlencoded

item=book&qty=1

HTTP/1.1 303 See Other
Location: /orders/5821
Content-Length: 0

In code

app.post('/orders', (req, res) => {
  const id = createOrder(req.body);
  res.redirect(303, `/orders/${id}`); // browser does GET /orders/:id
});

@app.post('/orders')
def create_order():
    oid = create(request.form)
    return redirect(f'/orders/{oid}', code=303)

Notes

• Unlike 302, 303 has the switch-to-GET behavior fixed by the spec, so it is unambiguous. Use 307 when the method must be preserved.
• The PRG pattern is the standard cure for the refresh-time resubmission warning ("Confirm form resubmission?").
• If you need HTTP/1.0 client compatibility, some servers fall back to 302 instead of 303.

Related status codes

Related headers

Specification