HTTP 303 See Other

What does HTTP 303 mean?

The client should fetch a different URL with GET. The textbook use is the Post/Redirect/Get pattern: after a form is submitted with POST, the server answers 303 pointing to a confirmation page, so refreshing the page does not resubmit the form.

3xx Redirection: The client must take another step — usually follow the URL in the Location header — to complete the request.

303 and SEO

Not used for moving pages; no SEO effect.

Example response

HTTP/1.1 303 See Other
Location: /orders/1001/confirmation

How to return a 303 response

Node.js (Express)

res.redirect(303, 'https://example.com/new-url');

PHP

header('Location: https://example.com/new-url', true, 303);
exit;

Python (Flask)

return redirect('https://example.com/new-url', code=303)

Go (net/http)

http.Redirect(w, r, "https://example.com/new-url", 303)

nginx

return 303 https://example.com/new-url;

Related status codes

• 302 Found — The resource is temporarily at a different URL, given in the Location header.
• 307 Temporary Redirect — Temporary redirect that keeps the request method and body.
• 201 Created — The request succeeded and a new resource was created.

Check which status code a URL returns with the HTTP header checker, or trace a redirect chain with the redirect checker.