? 308 Permanent Redirect

? Quick Overview

The 308 Permanent Redirect HTTP status code indicates that a requested resource has been permanently moved to a new URL, and all future requests should use the new URL. Unlike 301, it preserves the original HTTP method and request body.

? Key Concepts

• Belongs to the 3xx Redirection class
• Indicates a permanent URL change
• Preserves HTTP method (GET, POST, PUT, etc.)
• Client must reuse the same request body
• Introduced in HTTP/1.1 RFC 7538

? Syntax / Theory

When a server responds with status code 308, it must include a Location header containing the new permanent URL.

// HTTP response indicating permanent redirect with method preserved
HTTP/1.1 308 Permanent Redirect
Location: https://example.com/new-endpoint

? Code Example(s)

// Express.js example sending a 308 redirect
app.post("/old-api", (req, res) => {
res.redirect(308, "/new-api");
});

? Live Output / Explanation

? Interactive Example

Below demonstrates how a POST request is preserved during a 308 redirect, unlike 301 or 302 which may convert it to GET.

// Fetch API showing method preserved on 308 redirect
fetch("/old-endpoint", {
method: "POST",
body: JSON.stringify({name:"User"})
});

? Use Cases

• API version upgrades without breaking POST requests
• Permanent migration of form submission endpoints
• Secure endpoint restructuring
• RESTful service URL normalization