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HTTP 303 — See Other

? HTTP 303 — See Other

? Quick Overview

The HTTP 303 See Other status code tells the client that the requested resource is available at a different URI and should be retrieved using a GET request.

? Key Concepts

  • Used mainly after POST requests
  • Forces the next request to be GET
  • Helps prevent duplicate form submissions
  • Common in web applications and REST APIs

? Syntax / Theory

A 303 response includes a Location header pointing to the new URL. The browser automatically redirects using GET.

? Code Example(s)

? View Code Example
// Express.js example sending HTTP 303 redirect
res.status(303).redirect("/success");
? View Code Example
// PHP example for HTTP 303 See Other
header("Location: /thank-you.php", true, 303);
exit;

? Live Output / Explanation

What Happens?

The browser receives the 303 response and immediately performs a GET request to the URL provided in the Location header.

? Interactive Example

Click the button below to simulate a form submission flow. Watch the console to see how the POST turns into a GET.

? Form Page Ready to submit data...
// Network Activity Log waiting...

? Use Cases

  • Redirecting after successful form submission
  • Preventing duplicate POST requests on refresh
  • Clean navigation flow in web apps
  • REST API post-processing redirects

✅ Tips & Best Practices

  • Prefer 303 over 302 after POST requests
  • Always include a valid Location header
  • Use for user-facing redirects, not API errors

? Try It Yourself

  • Create a form and redirect using 303 after submit
  • Compare behavior of 302 vs 303
  • Inspect network tab to see request method change